 Lesson one of the elements of herpetology and ichthyology. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Recording by Nikalia. The elements of herpetology and ichthyology by William Ruchenberger. Lesson one, herpetology. Lesson one, general characters. Form, skeleton, motion, nervous system, senses, nutrition, apparatus of digestion, blood, respiration, lungs, temperature, secretion, eggs, classification. Class of reptiles. One, that part of natural history, which treats of reptiles, is named herpetology. From the Greek, erpeton, a creeping thing, a reptile, and logos, a discourse. Two, the class of reptiles comprises those oviparous vertebrate animals that have cold blood, an aerial respiration, and an incomplete circulation. They have lungs like mammals and birds, but their circulatory apparatus is always so arranged that a part of the venous blood mingles with the arterial, without having passed through the respiratory organ. And in general, this mixture takes place in the heart, which has a single ventricle, into which both oracles open. Three, in their general form, reptiles bear a closer resemblance to mammals than to birds. But in this respect, they vary very much. The head is almost always small, and the body much elongated. Sometimes they are entirely without extremities, or only possess vestiges of them. But most of these animals have four paws, formed for walking or swimming. Ordinarily, their extremities are too short to prevent the body from dragging on the ground, and instead of being parallel to the axis of the body and moving in this direction, they generally stand out from the side and move from without inwards, perpendicularly to the axis of the body, an arrangement very unfavorable to locomotion. Most reptiles seem to creep rather than walk, from which circumstance they derive their name. Four, the skeleton in reptiles is composed of almost the same bones as those we have already seen in mammals and birds, but it often happens that some among them are entirely wanting. Serpents, for example, have no extremities, nor have they any sternum, and frogs have no ribs. Five, the head in the arrangement of its bones resembles that of birds more than that of mammals. The cranium is small. The face is generally much elongated, and the lower jaw is suspended from a tympanic bone, which is placed between it and the cranium. In general, the head is articulated with the vertebral column by a single tubercle, or condyle, which has many facets and possesses only very slight mobility. Six, the structure of the vertebral column differs extremely in the different reptiles. In serpents, it is very long and very flexible. In frogs, it is very short and slightly movable, and in tortoises, its middle part is united so as to form a single bony piece. Seven, generally, the ribs are very numerous. In serpents, they exist through almost the entire length of the body, the same as the case in certain reptiles resembling lizards, while in others, these bones are merely rudimentary or entirely wanting. In tortoises, they are soldered, as it were, to each other, and with the dorsal portion of the vertebral column from the great shield or buckler which covers the backs of these animals and which is called carapax. Eight, without being as much developed, the bones of the shoulder are very analogous to those of birds. The anterior extremity consists of an arm composed of a single bone, the humerus, a forearm consisting of a radius and ulna, generally distinct from each other, and a hand which is sometimes in the form of a fin and sometimes resembling a foot. Nine, the movements of reptiles are, in general, less active and less sustained than those of animals with warm blood, as might be anticipated from the more limited character of their respiration. For there always exists an intimate relation between these two functions. Their muscles receive less blood and are of a whitish tint, and it is also remarked that these organs preserve their irritability for a longer time after they have been removed from the influence of the nervous system. In warm-blooded animals, the destruction of the brain and spinal marrow or a section of a nerve is at once followed by a complete paralysis, either general or local, and very soon after this phenomenon occurs, it becomes impossible to excite muscular contraction by pricking or otherwise stimulating the affected parts. In reptiles, on the contrary, the faculty of moving under the influence of stimulation is preserved under similar circumstances for a very long time. For example, the tail of a lizard detached from the body continues to move for several hours, and we may often see a tortoise that has been apparently dead for several days move its limbs when the muscles are stimulated by pricking them. We may conclude that in these animals, the division of the physiological labor and localization of the different functions of the nervous system are not carried so far as in mammals and birds, and hence there is a less intimate dependence of the different parts of the economy upon each other. 10. The encephalon of reptiles is but little developed. The surface of the brain is smooth and without convolutions. The two hemispheres are oval, more or less elongated, and internally hollowed by a single ventricle. The spinal marrow, compared with the brain, is very much developed, and it is also remarked that the nerves are longer proportionally to the volume of the central parts of the nervous system than in the superior animals. 11. Most reptiles have no special organ of touch, and the nature of their integuments prevents their tactile sensibility from being much developed. It is true that in some of them, the skin is entirely naked, and the epidermis is scarcely distinct, but for the most part, it is covered by a thick epidermic layer composed of horny or bony plates, which are more or less hard. In reptiles with a naked skin and an epidermis of moderate consistency, it is frequently detached and renewed, and in those animals where it is mostly consistent, it becomes detached at different seasons of the year to give place to a new epidermis. Sometimes this kind of molting is partial, or at least the epidermis only falls off in flakes. But at other times, it is entirely detached and preserves the form of the animal upon which it grew. Serpents shed their coats this way several times in the course of the year. 12. The eyes are ordinarily small, but in their structure are like those of mammals and birds, but there is rarely found in them any prolongation or fold of the retina resembling the pectin. The orbits are incomplete, and generally there is a third eyelid which is semi-transparent and moves traversely. 13. The structure of the ear is less complicated than in the superior animals. The external ear is almost always entirely wanting. There is no auditory canal, and the tympanum is on a level with the head and exposed or concealed beneath the skin. The organ of smell is but little developed. The nasal fossa are generally very small, and the pituitary membrane, the lining membrane of the nose, presents few or no folds. 14. Most reptiles swallow their food without chewing it, and their sense of taste appears to be very dull. The tongue is sometimes thick and fleshy, but in general it is thin, dry, very protractal, and often biped. It sometimes becomes an organ of prehension, the play of which is very remarkable. 15. Few animals live exclusively upon vegetable matter. Almost all of them are carnivorous, and with some exceptions, they hunt living prey which they generally swallow whole. The selection of the animals upon which they feed is, in a measure, regulated by the dimensions of their mouth. Most of them drink but little, and they can fast for a very long time without inconvenience. 16. The mouth is deeply cleft, and generally armed with teeth, which are sometimes found in the palate as well as in the jaws. They are almost always of a conical form, and, in general, in place of being lodged in alveoli, they are soldered, as it were, by their base to the bone that sustains them. In some reptiles that are without teeth, the jaws are covered by a horny plate, the edges of which are trenchant, like the beak of a bird. But they never have fleshy and movable lips like mammals. 17. Glandular organs and considerable numbers ordinarily surround the mouth of mammals, and pour into it either a gluey humor or saliva. Sometimes there are also glands very closely resembling salivary glands, which secrete a violent poison. 18. As it is not necessary for their food to remain in the mouth for mastication, a veil of the palate would have been, in general, useless, and, in fact, it rarely exists. In most of these animals, the pharynx is not distinct from the mouth, and often there is not a well-defined line of demarcation between the esophagus and stomach, which is simple and various in form. The intestines are short and without a cecal appendix. The large intestine differs little from the small and terminates in a cloaca. The liver is generally voluminous, and there is a gallbladder, pancreas, and spleen. 19. The blood of these animals is red, and its globules are elliptical. Their volume is much greater than in mammals and in birds, and the number of them is considerably less. The disposition of the circulatory apparatus varies, but there is always a direct communication between the vascular system of red arterial blood and the vascular system of black venous blood so that these two liquids mingle with each other, and the organs receive only blood, imperfectly arterialized by the act of respiration. The heart is almost always composed of two oracles, which empty into a single ventricle. Therefore, the arterial blood coming from the lungs and received in the left oracle, and the venous blood coming from different parts of the body into the right oracle, mingle in the common ventricle. One part of this mixture returns by the aorta to the different organs it is destined to nourish, and another goes to the lungs through the pulmonary arteries, which rise immediately from the common ventricle or from the aorta itself. It appears that in crocodiles, the heart is the same in form as it is in birds and mammals, and a partition separates the right ventricle from the left. Therefore, the arterial does not mingle with the venous blood, but there is a particular arrangement of the arteries which affects this mixture at a short distance from the heart, and the vessels of all the posterior half of the body only receive imperfectly arterialized blood. Until lately, it was believed that in other animals of this class, the Batrakeans, there was, on the contrary, but a single ventricle, but it has been demonstrated to be otherwise. 20. Respiration is carried on with little activity in reptiles. Most of these animals consume but little oxygen and can be deprived of it for a long time without becoming asphyxiate. Temperature exerts the greatest influence over this function, and in the warm season, the necessity of breathing is more vividly felt than in winter. A frog, for example, deprived of air in the summer, perishes in less than two hours, while in winter it will continue to live for several days. In some reptiles, there are Brancheae, gills, during the early period of life, but the lungs are soon developed and then the Brancheae disappear so that the same animal has at first an aquatic and afterwards an aerial respiration. There are some even that preserve these organs throughout life and which, having lungs at the same time, are completely amphibious, but most reptiles have lungs only. We must not conclude, however, that their respiration is exclusively aerial, for in many of these animals, the skin is also a respiratory organ and can act on the air dissolved in the water as well as upon the oxygen of the atmosphere. In some reptiles, this cutaneous respiration is even so active as to be, under certain circumstances, sufficient for the maintenance of life. 21. The organization of the lungs is not favorable to great activity of respiration. Their air cells are very large and consequently the vascular surface designed for contact with the air is but of little extent. They are not lodged in a particular cavity. The thorax not being separated from the abdomen by a diaphragm and the air is renewed in them with less facility and less regularity than in the superior animals. 22. Reptiles are all cold-blooded animals. That is, they do not produce sufficient heat to maintain a temperature above that of the atmosphere. Their whole body is warmed or cooled at the same time with the surrounding medium and the changes of temperature which they experience powerfully influences all their functions. A temperature of about 100 to 120 degrees of Fahrenheit's thermometer is promptly fatal to most of these animals and cold tends to abase all vital phenomena in them. 23. In winter most of them cannot digest substances taken in the stomach and they do not take food. Their respiration is also lowered in the most remarkable manner. A frog for example which in summer dies from asphyxia in less than two hours by the complete deprivation of atmospheric air or even by strangulation can in the cold season resist asphyxia for several days and live for many months without taking air into the lungs but solely by the assistance of cutaneous respiration. Reduction of temperature often produces in reptiles a lethargic state analogous to that of hibernating animals. 23. Except the production of poison in certain serpents the secretions of this class of animals are not particularly remarkable. 24. Having no means of suckling their young reptiles are reproduced like birds by the means of eggs. In some instances the eggs are hatched before they are laid and the animals in which this phenomenon takes place are said to be ovoviviparis. 25. This class is composed of four great natural divisions namely first the tortoises second the lizards and other reptiles resembling them in organization third the serpents and fourth the frogs and other reptiles of analogous structure. These four orders are designated under the names of Cologneia, Soria, Ophidia, and Betrachea. The principal characters which distinguish them may be seen in the following table. End of lesson one. Lesson two of the elements of herpetology and ectheology. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer please visit LibriVox.org. The elements of herpetology and ectheology by William Ruskenberger. Lesson two. Order of Cologneians or tortoises. Organization, division into four families land tortoises, freshwater tortoises river tortoises, sea tortoises tortoise shell its use. Order of Cologneia Greek tortoise Tortises are recognized at first sight by the curious defensive armor with which nature has provided them. A double shield envelops all parts of their body except the head and neck, the fore paws and tail which in general may be also concealed in this species of solid box. When studying the Bamelia we mentioned some animals that have the body protected by a sword of shell. The armadillo furnished an example but that armor formed only of a glutinated hair or by a particular modification of the epidermic layers of the skin and no wise resembles the double shield of the tortoises. For the latter is composed of bones which are widened and intimately united to each other. The carapax or upper shell is formed by the union of the ribs and dorsal vertebrae. The plastrum or lower shell is the sternum. Consequently these organs are a portion of the skeleton which instead of being lodged in the substance of the soft parts has become superficial and is only covered by a thin dry skin. The bony frame of tortoises to present this unusual disposition must be of course extremely modified. Still we find in it the same pieces which compose the skeleton of the higher vertebrate animals except that many of these pieces are changed in form and size. When we examine the carapax of a tortoise we see that it is formed of a considerable number of bony plates united to each by sutures and that eight of these plates occupy the middle line on each side of which 16 form a longitudinal row and 25 or 26 surround the whole like an oval frame. It is then difficult to recognize the nature of these bones but if we examine the carapax on its inferior surface we at once see that the middle pieces are simply dependencies of the dorsal vertebrae. In fact we find beneath it the body of each one of these bones of its ordinary form as well as the vertebral canal for the lodgement of the spinal marrow. But the superior portion of the parietase of the ring which constitutes this canal instead of having as as usual the form of a transverse bony band separated by a space from its fellows and being surmounted by a spinous process is here widened like a disc and without any interruption is continuous with the analogous plates belonging to the vertebra which proceeds and that which follows it. Each of these dorsal vertebrae in this way rendered immovable sustain a pair of ribs as in man and other vertebrata. But these ribs are widened so as to touch each other throughout or nearly throughout their whole length and join each other by sutures the marginal pieces which articulate with the extremity of the ribs and in a degree surround the carapax evidently represent the sternal portion of these bones which in mammals remain always in a cartilaginous state but in birds they are completely ossified. They also remain cartilaginous in some tortoises and many of them laterally support themselves by the edges of the sternal plastrum. The sternum of tortoises presents an extraordinary development it extends from the base of the neck to the origin of the tail and covers the whole inferior surface of the body. The pieces which enter into its composition are nine in number and instead of being placed in a row as in mammals with a singular exception they are arranged in pairs and soldered or articulated with each other so as to form a great oval plate. Sometimes this shield is entire and solid throughout its whole extent sometimes it is divided into three portions the anterior and posterior of which are slightly movable and other times it is hollowed in the center like a frame and it is fixed on each side to the carapax either by a broad bony prolongation or by cartilages and it is through a sort of slit or opening left betwixt these two shields or shells in front and behind this articulation that the head extremities and tail are protruded. The carapax and plastrum are only covered by the ordinary skin of this animal which is ordinarily scaly. No muscle is inserted into their surface and consequently the muscles of the neck and extremities are attached to the interior of the trunk. The shoulder instead of being sustained by the external parieties of the thorax is lodged in the interior of this cavity and the pelvis so to speak is contained in the cavity of the abdomen and the marginal pieces of the carapax are advanced beyond the base of the neck and tail so that these parts seem to project from the same cavities. The cervical vertebrae far from being immovable as they are on the back are so articulated with each other as to permit in general of extended movements similar to those of the neck of a bird. Their number is ordinarily eight and their articular surfaces are alternately convex and concave instead of being plain as in mammals. In some tortoises the neck is not retractile. In others it can be completely folded beneath the carapax either by bending downwards on itself or to one side. The head of tortoises is small compared with the body and the cranium is small compared with the head. Generally it is flattened and widened posteriorly by large temporal foci which are ordinarily concealed beneath the bony arch. The upper jaw is solidly fixed to the cranium and it is entirely immovable. The square or tympanic bone which supports the lower jaw is articulated in the same manner to the adjoining bones and forms the larger part of the vicinity of the frame of the tympanum. The lower jaw is composed of a great number of bony pieces. There are six on each side. The bones of the shoulder articulate on one side with the vertebral column and with the sternum on the other side form a sort of ring betwixt the carapax and plastrum through which pass the esophagus and trachea. We here observe three branches which often unite solidly with each other at an early age in which converge and form by their union the articular cavity of the humerus. One of these bones suspended to the vertebral column is evidently the scapula. The second which is directed backwards is analogous to the coracoid bone and the third which descends to join the plastrum is the representative of the clavicle or at least the acromion process of the scapula with which this bone ordinarily articulates. The pelvis resembles the ring formed by the bones of the shoulder. The extremities are not very remarkable in the disposition of their bony frame. They are always short, sometimes they are truncated at the end and at others flattened and elongated into a paddle, and in all the fingers are only slightly movable and in general they are not very distinct externally. The skin that covers the body of these animals sometimes preserves its softness and is not covered by scales, but in almost all of them it is furnished with a horny layer of very great consistency. These scales form large plates on the carapax and plastrum, the arrangement and aspect of which vary according to the species. Those which cover the carapax of a species of sea tortoise are remarkably beautiful and are employed in the arts under the name of tortoise shell. The eyes of tortoises are protected by three lids like those of birds. The tympanum is large but ordinarily concealed beneath the skin, and the nostrils are pierced through the extremity of the muzzle. As we have already stated, these animals are unprovided with teeth and jaws are furnished with a horny envelope with cutting edges like those of birds. Some live on marine plants and others on small animals as well as vegetables. They require little nourishment and they have been known to pass months and even years without eating. The elevator muscles of the jaw are very powerful and when a tortoise has seized hold of anything in the mouth it is almost impossible to get it away. The tongue is more complicated in its structure than that of most reptiles. It is thick and studded with filiform papillae. The stomach does not seem to differ from the neighboring parts of the digestive tube, except that edge is rather larger. The intestine is of moderate length and has no cecum. The liver is voluminous. The lungs are very large, enlarged in the same cavity with the other viscera. The mechanism by which the air enters them is entirely different from that of other animals in which the thorax is dilatable. The parieties of this cavity being immovable in most tortoises the air is forced into these organs by the action of the mouth. The jaws being closed the animal lowers the hyoid bone which enlarges the cavity of the mouth and the air having entered through the nostrils the posterior nares are closed. And then raising the hyoid bone as if to swallow the air thus enclosed is forced to descend through the trachea. Therefore the animal breathes by a sort of deglutition. Tortoises lay eggs with a hard shell which they deposit in the sand or earth in some situation exposed to the sun to cause them to be hatched. The males are generally smaller than the females and are ordinarily recognized by the plastrum which is slightly concave. The duration of life in these animals is very great. Authentic instances are known of land tortoises that have lived 120 years even 200 years and some cases of a still greater age are related. The habits of these animals vary and these differences which coincide with the modifications of their structure has caused them to be divided into four principal families their chief characters may be seen in the following table. Family of land tortoises having the feet large truncate at the end and formed for walking only and having the toes united in a common mass as far as the nails. Family of pond tortoises having the feet flattened and provided with distinct toes simply united by a palmate membrane incomplete carapax furnished with scales. Family of river tortoises having the feet flattened and provided with distinct toes simply united by a palmate membrane complete carapax covered by a soft skin. Family of sea tortoises having the feet flattened in the form of large swimming paddles and not having the toes externally distinct. Land tortoises testudo have feet formed for walking only their legs are as it were truncate and their toes are short and united to the nails their number is 5 in front and 4 behind the carapax is very much vaulted and they can draw the head tail and extremities completely within their shell they live in the woods or in places well furnished with herbage they never go into the water but often inhabit its neighborhood most of them feed chiefly on vegetables and terrestrial mosques they make a kind of burrow and in temperate climates past the winter in a state of hibernation their eggs are generally spherical and furnished with a hard shell the female deposits her eggs in a hole and seems to take no care of her young the most common european species is the greek tortoise testudo grechia which is yellow spotted with black and about 6 inches long it inhabits greece idly france in the large islands of the Mediterranean in idly and sicily this species is often eaten the family of pond tortoises or fresh water tortoises emus much more numerous than the proceeding forms a sort of connecting link with the land tortoises and those that are essentially aquatic it is composed of chelonians that commonly live in marshes and can swim but yet differ very little from the proceeding in their organization they are chiefly distinguished by the confirmation of their paws the toes five in number are distinct movable furnished with hooked nails and united at their base by a palmate membrane of greater or less extent but these characters are not always clearly marked as in land tortoises the carapax is in general entirely solid and oval in form but instead of being elevated it is more or less depressed the neck is almost always longer than in the proceeding and presents remarkable variations in its confirmation and some it is cylindrical and surrounded by a loose skin which permits it to be entirely drawn within and in the middle part of the carapax well and others covered by a close cutaneous sheath which adheres to the muscles so that it can only be folded laterally on the body almost all of them can conceal their paws between their shells and like the proceeding they have about four nails on the hind feet their motions are not as slow as those of the land tortoises and they swim with considerable facility their chief food consists of fluviatile mollusks, vitrachians and analytes found on the margins of lakes, marshes and rivulets in which the current is not rapid the genus of cestudes belongs to the division of freshwater tortoises with a retractile neck it is distinguished by the sternum which is furnished with twelve plates and divided into two nearly equal parts both movable and by the short tail the european cestude or mud tortoise testudo europeo has a depressed carapax very smooth blackish with yellow points and about six inches long it inhabits stagnant waters at the bottom of which it loves to keep buried in the mud on the approach of the cold season it retires into holes to hibernate it is found in the south of france but it is particularly common in Greece and Italy its flesh is used as food and it is reared for that purpose with bread, young vegetables, etc some freshwater tortoises there is external plastic divided into two flaps which they can at will by a movable articulation close against the carapax when their head and extremities are drawn in so as to enclose themselves in a box this peculiarity has obtained for them the name of box tortoises there are some freshwater tortoises on the contrary that cannot enclose themselves within the shell amongst these is the snapper testudo serpentina which is readily distinguished by its long tail which is studded with sharp crests it is found in the warm parts of the United States the family of river tortoises or soft-shelled tortoises trionikes differ from all proceeding in the conformation of their paws which are designed for swimming but are entirely unsuited for walking the paws are very much depressed and the toes, although very distinct and more or less movable as far as the nails by broad flexible membranes the carapax is very much spread out and almost flat unprovided with scales covered only by a skin which is soft and entirely cartilaginous throughout its border which structure has obtained for them the name of soft-shelled tortoises the neck is generally elongated and protractile the nostrils are prolonged into a sort of little trunk the jaws are trenchant and furnished with a fold of skin which resembles lips the limbs are short and supplied with only three toes to these external characters are added other anatomical peculiarities for example the carapax has no marginal paces and the sternum is not ossified in the middle these animals are essentially aquatic and inhabit the rivers and lakes of the warmest regions of the globe they swim with great ease and remain on land only at night they are very voracious and feed chiefly on reptiles and fishes the Nile supports one species of these tortoises which is useful to Egypt by devouring a great number of young crocodiles the moment they are hatched it is the Tyrese Trionix egyptiacus of zoologists another species which inhabits the rivers of South America is remarkable for its ferocity and for the delicacy of its flesh the family of sea tortoises turtle chelonia the tortoises that live in the sea differ from all others both in their conformation and habits their flattened paws which are really paddles are only suited for swimming and their toes which are closely pressed together and enveloped in the same membrane are entirely immovable only the two first toes of each foot have nails and these fall off at a certain time in the interior extremities being of nearly the same length as the posterior are more than twice as long the carapax is arched in cortiform and near the edge of this shell the ribs are not widened and soldered together as in the preceding family the sternum is in the form of a frame open in the center the nostrils are not prolonged into a trunk but are surmounted by a fleshy mass which acts like a valve and closing these openings when the animal puts its head under water the edges of the beak are very trenchant and the upper mandible is hooked these tortoises feed principally on marine plants and only leave the water in the laying season they swim with great facility and they are sometimes met several hundred leagues from land floating on the surface of the sea they appear to be able to sleep in this way and they also dive very well at the laying season they leave their habitual haunts and resort to the shores of some desert island to deposit their eggs in holes which they dig upon the beach during the night the females leave the water for the purpose of laying they drag themselves on the beach beyond the line of high tide and with their interior extremities excavate a hole about two feet deep in which they deposit their eggs in regular ranges and cover them with sand which they level off so carefully as to leave scarcely a trace of their labor the operation is over they turn immediately to the sea the number of eggs is very considerable sometimes as many as two hundred and the laying is repeated two or three times a year after exposure to the sun for fifteen or twenty days they burst and the young which are not yet provided with shell immediately make for the sea generally they find difficulty at first in plunging into it and before reaching it they often become the prey of carnivorous birds which seem to await the moment of their birth to feast upon them they have also to dread voracious fishes and crocodiles which assemble in the same places for the same purposes the most part of these which escaped their numerous enemies acquire very considerable dimensions they have been known to measure fifteen feet in circumference and to weigh from five to six hundred pounds marine tortoises are found in all warm seas they abound about the west Indies and particularly about a small archipelago near the main known under the name of Tortugas among these tortoises we distinguish the Chalonia in which the carapax is covered with horny plates or scales and the Sphargus which have only coryaceous skin the most common species of the first of these genre are the green tortoise turtle, the carrot or hawksbale turtle, and the Cayunane only one species of Sphargus is known, the luth the green tortoise to Stuto Viridis is recognized by the plates 13 in number and not arranged like tiles that cover the disc of the carapax which is fond color with a number of ground spots glazed green it is found in the Atlantic ocean and feeds chiefly on a plant known to botanists under the name of Zostera Marina it lays twice a year about the months of May and June and the total number of eggs is about 250 its length is sometimes from 6 to 7 feet and its weight from 7 to 800 pounds this species differs very little from other marine tortoises frequenting the same places and is found on the coasts of Africa and in the Asiatic seas the flesh of all these Chalonians is very much esteemed in England particularly it is very much sought as a luxurious dish and to supply the London market vessels are dispatched to the Indian seas and on certain coasts parks have been established for the preservation of sea tortoises the fat of these animals although of a greenish hue which may be at first unpleasant has a very delicate taste and their eggs are equally esteemed the Ku'ain to Stuto Coretta as in the green tortoise the carapax is covered by plates simply placed together the head disk is 15 instead of 13 the head is also larger and its color is brown or deep chestnut it inhabits the Mediterranean as well as the Atlantic Ocean it does not attain the same size as the proceeding its length is about 4 feet and its weight from 3 to 400 pounds it is very voracious its food consists chiefly of mollusks and its flesh is not good its fat is burned for light the honksbill turtle the carrot is the most interesting species of this genus because it furnishes the tortoise shell it is readily distinguished by the arrangement of the horny plates of its carapax which in place of being simply joined together are extended backwards one over the other like the tiles or shingles of a roof we count 15 on the disk the color is yellowish marble with a deep brown the jaws are strong, elongated and curved towards the extremity but without teeth on the edges the extremities or fins like those of the Cayoaine are provided with two nails while in the green tortoise there is about one its size scarcely exceeds one third of that of the last name Chalonian it feeds chiefly on marine plants but also eats crustacea, molluska and small fishes it is met in the Indian Ocean and in the laying season resorts to the same localities as the preceding species at the tutugas for example it arrives in June and lays a second time in August the total number of its eggs is about 200 they are said to be good food but the flesh of this tortoise is bad and it is only on account of its shell that it is sought the scale or shell which covers the carapax of the hawksbill is a substance which is extremely analogous to horn but which is neither fibrous nor lamellar like it it is as transparent its hardness is greater and it is capable of receiving and preserving the most beautiful polish and it is very much esteemed in the manufacture of toys etc each one of these tortoises furnishes on average from three to four pounds of these large scales and to detach them it is only necessary to expose the carapax before burning coals it is brought to market without any other preparation and is known as rough tortoise shell which is afterwards manufactured in the same manner as horn by softening it by the action of hot water and afterwards pressing it can be spread out, soldered or molded into any required shape what is termed run or cast shell is obtained by agglutinating by a similar process the scrapings and powder detached from the ordinary shell or giving it the desired dimensions the marine tortoises designated under the name of Sphargos have no covering composed of horny plates but one of a coreaceous skin similar to leather only one species is known, the Loth which is found in the Mediterranean and the Atlantic it attains seven or eight feet in length end of lesson two lesson three part one of the elements of herpetology and ichthyology this is a LibriVox recording all LibriVox recordings are in the public domain for more information or to volunteer please visit LibriVox.org the elements of herpetology and ichthyology by William Ruskenberger lesson three part one order of soria organization classification family of crocodilida circulation, habits crocodiles, properly so called locators family of lecertinida characters, monitors, lizards family of iguanida characters, dragons, iguanas, basilisks family of gecotida characters, habits family of chameleonida characters, common chameleon family of skinkgoida characters, skinks fossil soryans order of ophidia or serpents characters, family of anguina characters, family of serpentia or true serpents colibur, boa venomous serpents, rattlesnake trigonacephalus vipers, neia or asps affects and treatment of the bites of vipers etc. family of nuda characters order of soryans the order of soria comprises all reptiles that resemble lizards in their general conformation animals of this order always have an elongated body terminated by a tail of greater or less length and provided with extremities which, with some exceptions are four in number their extremities are short and placed unfavorably for rapid movement in general they are wide apart and directed outwards at a right angle with the body so that they cannot sustain the weight of the trunk reptiles drag the belly and tail on the ground the toes which are very distinct and ordinarily five in number terminate in sharp curved nails sometimes they are very long and slender at others widened and furnished beneath with folds variously arranged and at other times again united by palmate membranes which modifications are in conformity with the animals mode of life the skeleton has no important remarkable peculiarity the number of vertebrae is very variable particularly in the caudal region there always exist movable ribs which often protect the abdomen as well as the thorax the sternum is never wanting the shoulder is ordinarily formed of three bones a scapula, a clavicle and a coracoid bone united in a kind of ring so as to envelop the interior part of the chest and all concur in the formation of the cavity designed to lodge a humerus the pelvis is also composed of three pieces and is joined to the sacrum which consists of two vertebrae the skin of these animals is always covered by a thick and unequal epidermic layer which forms scales or plates of greater or less size the mouth which is deeply cleft is without fleshy lips it is armed with teeth generally of a conical form that serve to seize and hold their prey but rarely to grind their food is often found in the palate as well as in the two jaws the food of Saurians consists essentially of animal substances the digestive canal is ordinarily quite short in general the stomach is scarcely distinguishable from the esophagus but sometimes it has the form of a more or less globular pouch the disposition of the circulatory system varies in these animals in general the heart is but imperfectly divided in its ventricular portion so that the venous blood and arterial blood mingle in its interior but in crocodiles the separation between the two halves of this organ is complete and the mixture of the two kinds of blood takes place only in the descending aorta the lungs in general are large and extend more or less into the abdomen the air is renewed in them by the same mechanism as in mammals and birds that is by the alternate dilation and contraction of the cavity of the thorax affected by the action of the ribs the order of Saurians may be divided into six families namely crocodilians, lacerdeans chameleonians, iguanians gecoteans and skinkoideans which may be distinguished by the following characters crocodilians Saurians having four toes on the hind and five on the fore feet tail compressed, tongue not extensile and the heart with four distinct cavities lacerdeans Saurians in general having five toes throughout and always the same number on the interior and posterior paws the heart with but three cavities tongue very extensile bifid at the end toes free, tail not prehensile chameleonians Saurians in general having five toes throughout and always the same number on the same interior and posterior paws the heart with but three cavities tongue very extensile terminated by a fleshy cylinder toes united in two opposable parcels, tail prehensile iguanians Saurians in general having five toes throughout and always the same number on the interior and posterior paws the heart with but three cavities tongue not extensile paws quite long body neither fusiform nor vermaform toes unequal and not widened at the end body light gecoteans Saurians in general having five toes throughout and always the same number on the interior and posterior paws the heart with but three cavities tongue not extensile paws quite long body neither fusiform nor vermaform toes equal and almost always widened at the end body neither fusiform nor vermaform of a disc or fan body squat skinkodians Saurians in general having five toes throughout always the same number on the interior and posterior paws the heart with but three cavities tongue not extensile paws in general very short and often only two in number body fusiform or like that of a serpent certain fossil reptiles are also referred to in this order some of them were formed for swimming exclusively and others for flight family of crocodilians crocodilians differ in so many respects from other Saurians that many authors think they ought to constitute a separate order their internal organization seems to place them as a connecting link between reptiles in the higher vertebrata they are very easily recognized by their laterally compressed tail and by their toes five before behind all of them more or less united by membranes which is indicative of aquatic habits the most remarkable peculiarity in the structure of these animals is the disposition of their circulatory system it is such that the whole posterior part of the body receives only a mixture of arterial and venous blood while the head is supplied with pure arterial blood the heart has four cavities two oracles and two distinct ventricles as in mammals and birds the arterial blood coming from the lungs passes from the left oracle into the ventricle of the same side which in its turn sends the blood into the aorta the venous blood received into the right ventricle finds no direct passage into the left ventricle as is the case in other reptiles but it does not all go to the lungs as it does in the warm-blooded vertebrata for alongside of the pulmonary arteries is found another vessel which also arises from the right ventricle and which after bending backwards behind the heart terminates in the descending aorta it follows therefore that at every contraction of the heart one portion of the venous blood is sent to the lungs and another portion is mangled with the arterial blood but this mixture takes place in the interior of the aorta below the point of origin of those branches which this vessel sends to the head and interior part of the trunk so that these parts receive pure arterial blood while all those the arteries of which arise posteriorly to the point of junction between the aorta and the vessel coming from the right ventricle receive only a mixture of red and black blood the lungs of crocodiles do not extend into the abdomen like those of other reptiles and are separated from its viscera by a sort of imperfect diaphragm it is also to be remarked that the canal through which the air penetrates to these organs can be completely separated from the mouth by letting down a fold analogous to the veil of the palate and mammals an arrangement which permits them to remain underwater with the mouth open to await their prey without interrupting their respiration and their nostrils which open at the extremity of the muzzle are closed by valves their mouth is cleft beyond the ears and the lower jaw is prolonged backwards beyond the cranium which makes the upper one seem to be movable but it only moves with the cranium there is in each jaw a single row a very strong pointed teeth planted in distinct alveoli the tongue is fleshy flat and attached to the lower jaw very close to its edges and hardly distinct from it which led the ancients to believe that it was entirely wanting the stomach is in the form of a rounded pouch the skeleton also has several peculiarities the cervical vertebrae rests one on the other through the medium of small false ribs which renders lateral motion difficult besides the ordinary ribs there is found between the muscles of the abdomen analogous bones which protect the viscera without extending to the dorsal spine these reptiles are the only Saurians that want clavicles properly so called crocodiles are large animals their back is covered by large square very strong scales which are caranate bridged in the middle their tail has a similar covering and is furnished on the top with a strongly notched crest which is double at its base the plates on the belly are thin smooth and square and arranged in transverse bands these large and powerful animals inhabit the hottest parts of both continents and ordinarily keep in freshwater rivers and lakes their gait is usually slow though they can swim with extreme rapidity and run very swiftly in a straight line but owing to the disposition of the vertebrae of the neck it is difficult for them to change their direction hence it is easy to avoid them by turning or running around them they are very carnivorous and formidable even for man they cannot swallow in the water but they generally drag their prey there to drown and it is said they deposit it in some hole to putrefy before eating it these animals notwithstanding they are so formidable and so well furnished with protective armor have foes to dread and these enemies are feeble insects a sort of ant which introduce themselves into their mouths in immense numbers the moment they go on shore and torment them with their stings but what is very singular little birds often come to deliver them from this scourge and enter their great mouth without fear in pursuit of the insects this fact, observed by Herodotus and afterwards treated as a fable has been confirmed in modern times by Geoffrey Saint-Hilaire who accompanied the emperor Napoleon in Egypt a species of plover performs this interesting service for the crocodiles of the Nile and in the West Indies the toadie has a similar habit the family of Crocodilida is composed of three genre namely crocodiles properly so called caimans or alligators and gavels crocodiles properly so called crocodilings having the muzzle wide in the whole head oblong the upper jaw simply notched on each side to receive the fourth tooth of the lower jaw caimans crocodilians having the muzzle wide in the whole head oblong the upper jaw with a hole on each side to receive the fourth tooth of the lower jaw gavels, crocodilins having the muzzle slender and very much elongated Crocodilus, properly so called, crocodilus, have an oblong and depressed muzzle, unequal teeth, and the upper jaw notched on each side to receive the fourth lower tooth when the mouth is shut. The most celebrated and longest known species is the crocodile of the Nile, an animal that is sometimes twenty-five and even thirty feet in length. It is bronze-green, spotted and marbled with brown above, yellowish-green below, and is distinguished by the square plates, nearly equal in size, which form six rows along the back. We find, from Senegal to the Ganges, even beyond it, crocodiles very similar to that of the Nile, which seem to be only varieties of this species. Formerly, this reptile descended the Nile to its delta, and according to Pliny, passed the four winter months there in caverns. But in our time it never quits upper Egypt, where it does not hibernate. The ancient Egyptians, particularly the inhabitants of Thebes, and the environs of the lake Moris, rendered great honors to these reptiles. They even made them objects of religious worship, and embalmed their dead bodies. At Arsinoe, the priests raised one of these reptiles, which they kept in a temple and adorned with jewels and fed with great care. The caverns of St. Domingo and other parts of the West Indies belongs to this genus, and has received the name of Crocodilus acutus, or sharp-nosed crocodile, from the form of its head. It has four rows of plates on its back, and its length sometimes exceeds sixteen feet. It is a fierce and dangerous animal. At birth the young are from nine to ten inches long, and growth continues for twenty years. The caverns, or alligators, are readily distinguished from crocodiles properly so called, by the disposition of the fourth tooth of the lower jaw, which, when the mouth is closed, is lodged in a hole, and not in a notch of the upper jaw. Their hind feet, in place of being notched on the external edge, and palmate to the end of the toes, are unprovided with notches, and are only semi-palmate. Many species are known, but all seem to belong to America. One of them, the pike-nosed alligator, Crocodilus lusius, inhabits the southern parts of North America and during the season of ice buries itself in the mud, and remains benumbed until the return of a milder temperature. In Guiana and Brazil there is another, the spectacle alligator, Crocodilus sclerops, so called from the ridge which unites the projecting edges of the orbits in front. Like other crocodiles the last lays its eggs in the sand, but covers them with straw or leaves, and instead of abandoning them, defends them courageously. It is from twelve to fifteen feet in length and rarely attacks man. The gavials differ from the two preceding genre in their very long slender muzzle, as well as in their teeth, which are nearly equal. They are only met with on the eastern continent. The most common is the gavial of the Ganges, Lacerda ganjatica, which is said to attain thirty feet in length, but is not dangerous either to man or large animals. It feeds exclusively on fishes. Family of Lacerteans The Lacerteans have five distinct toes on all their feet, armed with nails. The tongue is thin, extensile, and terminated by two threads. Their scales are arranged in transverse and parallel bands around the tail and under the belly. Some have teeth in the jaws only, and others have them also in the palate. The first form the tribe of monitors, and the second that of lizards. The monitors generally have a laterally compressed tail, like that of a crocodile. Monitors properly so-called are recognized by the small scales that cover the head, limbs, and whole body. Two species are found in Egypt. One, the monitor of the Nile, Lacerte nylotica, is five or six feet long, and is seen sculptured on the monuments of the ancient Egyptians. The other, called the land monitor of Egypt, on account of its terrestrial habits, is common in the deserts, in the vicinity of that country. Other monitors, called sovagards, have the top of their head furnished with angular plates, and the belly and tail are covered with large rectangular scales. The tribe of lizards is composed of lizards properly so-called, and some similar genre in which the palate is armed with two rows of teeth and the tail is cylindrical. Most of them are also distinguished by a sort of collar placed under the neck and formed of a transverse range of larger scales, separated from those of the chest, by a space covered only by granulations. In general they have also, under each thigh, a longitudinal series of projecting pores, and the whole top of the head is armed with a bony shield, which is covered by large, horny plates. Lizards properly so-called, Lacerte, have the top of the body covered by small scales similar to granulations, while beneath the belly they have large transverse plates. These animals are agile, light and elegant in form. They feed principally on insects and prefer a living prey. In summer they eat a great deal, but they can easily support a fast of several weeks in summer and four or five months in winter. When held in captivity they generally refuse to take food, yet they bite at everything presented to them and close their jaws with considerable force. In our climate they pass the winter benumbed in holes, and their movements are active in proportion as the temperature is more elevated. They love to warm themselves in the sun, even in mid-summer, and they are often seen stretched on a stone, basking in the sunshine. Many fables have been attached to these animals. Some have pretended without any reason that they are venomous. Others, without foundation, assert that they show a true attachment for man, and give him warning when a serpent is about to bite. A great many species are known. Family of Iguanians The Saurians composing this family have very nearly the same general form as the Losertians. They also have a long tail, free and unequal toes, etc., but their tongue is fleshy, thick, not extensile, and only notched at the end. The mouth presents the same modifications as the preceding family. Sometimes they have teeth in the palate as well as in both jaws. Sometimes there are only two ranges of teeth in the upper jaw. Among the first are ranged the Stelios. They have the tails surrounded by large scales, which are often spiny. The Iguamians, in which the scales on the tail are imbricate, that is, having the scales lying over each other like shingles on a roof, and not verticalate, that is, not arranged in a circle around a center, the dragons, etc. The last are distinguished from all other reptiles by a species of wing formed on each side by a deep fold of skin. These appendices resemble the wings of a bat, but instead of being supported and set in motion by the extremities, they are altogether independent of them, and are sustained by the first six false ribs, which do not surround the abdomen, but are extended horizontally in a straight line. The animal uses these wings as a parachute to sustain itself in the air when it leaps from branch to branch, but it cannot use them with sufficient force to fly like a bat or a bird. These singular reptiles, which inhabit India, realize to a certain extent the fable of flying lizards or serpents spoken of by certain ancient writers. But the dragons of zoologists, instead of being formidable animals, like those of the poets, are of a very small size and only attack insects. As examples of Iguanians with palatine teeth, we will mention Iguanas properly so called, basilisks and enolis. The first are covered by small, implicated scales and have a crest of pointed scales along the back. There is also observed beneath the throat a pendant and compressed doolap. Several species are known, which inhabit America. One, four or five feet in length, is common in all the hot regions of the new world. It lives mostly on trees and feeds on fruit, leaves, etc. Its flesh is reputed delicate, but unwholesome. The basilisks, basiliscus, have along the back and tail a continued elevated crest, which is supported by the spinous processes of the vertebrae. They feed on grains and inhabit guiana. The enolis, enolius, which also belong to America, are distinguished by the conformation of their toes. The antipenultimate joint of which is furnished on the underpart with an oval striated disk by the assistance of which these reptiles cling to the surface upon which they climb. Many of them possess the power of changing the color of their skin. To the family of Iguanas also belongs an enormous reptile called Mosasaurus, the fossil bones of which have been found at Maestricht. Family of Gekotians The Saurians designated under the collective name of Gekos are nocturnal animals, dull and heavy in appearance. Their walk is crawling and their swat and flattened form is in striking contrast with that of most of the reptiles we have here too forementioned. Their head is wide and depressed, their eyes are very large and very prominent, their jaws are armed all round with a single row of small teeth, but there are none in the palette. Their tongue is fleshy and not extensile, the body is studded above by small granular scales among which are larger tubercles, the whole resembling chagrin, and covered beneath by flat, implicated scales. Their feet are moderate in size and their five almost equal toes are ordinarily widened throughout or in part armed with retractile nails and furnished beneath with a fold of skin by the aid of which they adhere to bodies upon which they walk. This confirmation of the toes enables them to walk easily on the smoothest walls and even upon ceilings. During the day they conceal themselves in obscure places and at night, more especially, they seek spiders and other animals upon which they feed. The ugliness of these reptiles is extreme and we are assured that the contact of their feet on our skin often excites a sort of inflammation. They are everywhere objects of aversion and they are charged with being venomous but this opinion is not sustained by positive proof. The geckos are very numerous and disseminated throughout the warm parts of both continents. Family of chameleons. The chameleons, chameleo, are distinguished from all other psorians by their toes which are five in number on all their feet but divided into two opposable parcels or bundles in arrangement which makes these animals essentially climbers destined to live on the branches of trees. A number of peculiarities of organization separates them from all the reptiles we have thus far considered. Their tail, round and prehensile, serves them as a fifth extremity in suspending themselves from branches and aids them in their slow and awkward movements. Their eyes, which are very large and very projecting, are almost entirely covered by the skin. The light reaches them only through a little hole, situate opposite to the pupil, as these organs move altogether independently of each other. Their mouth is armed with small trilobed teeth and their tongue, fleshy and cylindrical, is extremely extensile. They can dart it out of their mouths to a distance that sometimes exceeds the length of the body and they use it to seize living insects upon which they feed. Their body is compressed and the back is ridged or, as it were, trenchant and the skin is covered by small scaly granulations. These singular animals are celebrated for their faculty of almost instantly changing color. And if we believe the ancient writers, they even possess the power of assuming successively the use of all the objects by which they are surrounded in order to conceal themselves more effectually from their enemies. The observations of naturalists have already robbed the history of the chameleon of the fables with which it was loaded. And although the faculty of changing its colors in this manner has been denied, it has been ascertained that it really undergoes the most remarkable changes, being sometimes almost white, sometimes yellowish, at other times green, reddish, and even almost black, either entirely or only on parts of the body. These changes are particularly observed when the animal is excited, either by anger or by heat. When it has remained for some time in a dark, cold place, it is almost white, and warming it or stimulating it causes it to assume a bottle green or vines red hue, which often becomes so intense that it appears to be almost black. For a long time these changes were attributed to the greater or less distention of the very large lungs of this animal and to corresponding modifications in the quantity of blood sent to the skin. But we are assured there is no necessary relation between these phenomena, and dissection of the skin teaches us that we must seek the cause of these variations of color in the particular mode of the structure of this membrane. We find in fact that it contains different coloring matters, some of which can sometimes rise to the surface and in a degree mask the others and at other times retire and become hidden beneath the superficial pigment. Only a single genus of Saurians possessing the above described organization is known. Many species of chameleons have been ascertained. One of them, very common in the neighborhood of Algiers, is met with from Spain to the Indies. Family of Skinkoidia. The Saurians which compose this family are recognized by their short feet, their tongue, which is slightly or not at all extensible, and by the equal and ordinary implicated scales which cover the body above and below. Some of them are spindle shaped and others have the body so much elongated and the tail not very distinguishable from it, that they resemble serpents. In many the feet are too short to serve for locomotion and there are some in which one pair of extremities, either the anterior or posterior, is entirely wanting. The Skinkoidia evidently form the connecting link between the Saurians and Ophidians. Among the Skinkoidia, we place the skinks, the seps, the bipeds, the Chalkides and the Bimana. In the first two genre, there are four feet, and in the seps the body is more elongated and more verma form than in the skinks. The bipeds and Chalkides want the interior extremities and the Bimana have the four feet only. Long previous to the epic of the creation of man, there existed on the surface of the globe a great number of gigantic reptiles, the bones of which are found in a fossil state. Only Saurians, the race of which is extinct, are found to the Sardians, resembling monitors that must have been from 30 to 40 feet in length, but many of those lost animals are particularly remarkable for their anomalous structure. In England, near Hanfleur, and in other localities, we find in the very ancient formations the remains of many species of two genre of Saurians whose broad feet in the form of battle Saurians indicate that these animals were entirely aquatic. They are designated under the names of Pleososaurus and Ictosaurus. And another reptile, still more extraordinary, has been discovered in some of the ancient layers of the earth. According to the structure of its bony frame, we see, like the bat, it must have been capable of walking and flying, for its posterior extremities and all the toes of the four feet, with a single exception, are formed in the ordinary way. But the second toe of the anterior extremities is more than twice as long as the body and probably sustained a fold of skin fitted to perform the functions of wings. To indicate this singular confirmation, the generic name of Pterodactylus has been given to these Fossil Saurians. End of Lesson 3, Part 1. Lesson 3, Part 2 of the Elements of Herpetology and Ictheology. This is a LibriVox recording. All LibriVox recordings are in the public domain. From our information or to volunteer, please visit LibriVox.org, recording by Amy Graymore. The Elements of Herpetology and Ictheology by William Ruskenberger, Lesson 3, Part 2. Order of Ophidians or Serpents. We ordinarily group with serpents or Ophidians all reptiles that have a cylindrical, elongated body without extremities. But in order that the classification of these animals may represent the modifications introduced by nature in their organization and indicate the degree of physiological importance of these differences, it becomes necessary to separate from the serpents some apotis reptiles in which respiration is at first bronchial, then pulmonary, as it is in ordinary betrackians. On the other hand, the passage between the Saurians and Ophidians is so gradual that the limits between these two orders are somewhat arbitrary. Some naturalists even think they should not be separated and according to others, it would be proper to range in the division of Saurians. Those reptiles that, by their internal organization, are removed from the common type of Ophidians and approach that of skinkordia. The apotis reptiles which are in a manner intermediate between the Saurians and the serpents, properly so-called are the snakes or anguies, anguina. They are easily distinguished by the imbricate scales which cover the body like those of skinkordia. They also approximate the Saurians by the presence of three eyelids, organs that are not found in true serpents. The tongue is fleshy and but somewhat extensile and the bony skull possesses the same confirmation as that of the skinks and we find beneath the skin of most of these animals, vestiges of a pelvis and shoulder bones. On the other hand, they resemble true serpents in the general form of the body and in the small size of their lungs. They are very mild animals and when taken hold of do not attempt to bite. Their mouth is small and armed with teeth like those of the skinkordia. They feed on different insects and terrestrial mollusks and entirely conceal themselves in holes and are torpid in winter. Their tail, like that of lizards, breaks with the greatest facility and some anguies stiffen themselves so much when taken that the body breaks, which singular circumstance has obtained for them the name of glass snakes. Common anguie of Europe, anguies fragilis, is about a foot long and its tail, which is obtuse and like the rest of the body is of the same length as the latter. Its scales are smooth and shining. It is blackish beneath and of a yellowish lead color above with three black bands, which as it advances in age, change to a series of points and finally disappear. It has no external tympanum. It digs subterraneous galleries and produces its young like vipers in which the eggs are hatched before they are laid. The true serpents, Serpentia, possess no internal trace of anterior extremities. They have no vestige of sternum or shoulder, but many of them have beneath the skin rudiments of posterior extremities which sometimes show themselves externally in the form of a small hook. The skin is furnished with scales which in general are small and imbricate above and in the form of broad quadrangular plates beneath. They have no tympanum and their eyes appear to be entirely without lids for they are only covered by a sort of single and immovable veil which is set in like a watch glass in front of the orbit and which permits the passage of light. The vertebrae and ribs by themselves form almost the whole skeleton of serpents. Their number is very considerable. In the viper we count 198 vertebrae, in the boa 304 and in the ringed snake 316. The form of these bones is nearly the same throughout the column and their mode of articulation is very remarkable. The interior part of the body of each vertebrae presents a rounded semi-sophirical tubercle which is received in a corresponding cavity on the posterior face of the vertebra next to it. This mode of articulation explains the movements of the body of these animals which in general are executed laterally and not from above downwards. In fact, the spinous processes which prevails along the back are ordinarily so disposed as to prevent the vertebral column from bending very much in this direction. The ribs surround a large part of the trunk and are wanting only in the caudal vertebrae. The first pair are smaller than the others but they commence at the head so that these animals have no neck. We count in some instances as many as 250 pairs. Serpents are essentially carnivorous. They can endure abstinence for a long time but in general when the opportunity occurs they gorge the stomach with such a quantity of food that during digestion they remain in a state of greater or less torpor. They do not chew their food but their mouth is armed with hooked teeth suited for retaining their prey. Their tongue is very extensible and terminates in too long semi-cardilogenous and very movable filaments. The digestive canal is very short and the stomach is merely a slight dilation of this tube. The circulation is carried on in the same manner as in tortoises and psorians except crocodiles. The heart is composed of two oracles and a single ventricle incompletely divided into two cavities from each one of which arises an aorta which joins its fellow behind this organ. The lungs are very unequal in size and generally one of the two is entirely atrophied while the other is very large and prolonged into the abdomen above and beyond the stomach and the liver. It is in the form of a large membranous sac in the interior of which are found great polygonal cells. The air is renewed in them by the motions of the ribs and abdominal muscles nearly in the same way as it is in the psorians and birds. Probably it is in part owing to the position of the lungs that serpents become torpid after a copious repast. For every time they swallow a prey of large size this organ must be compressed and the pulmonary circulation impeded. The structure of the head varies in these animals. Sometimes the lower jaw, the two branches of which are solidly united in front is supported on a tympanic bone which is itself immediately articulated with the cranium as in psorians and chelonians but in general the tympanic bones are movable. The true serpents with immovable tympanic bones also have the upper jaw fixed to the cranium and the mouth but little dilatable. They form the small family of double walkers, amphibema, so-called from their faculty of moving equally well both forward and backwards. Those that form the genus of amphibena have the body surrounded by circular ranges of small quadrangular scales like certain skinkoids. The others, called typhlops, have small imbracate scales and at first sight resemble earthworms. These ophidians inhabit the warm countries of both continents. Some of them are blind. True serpents having movable tympanic bones form a more numerous family. Some of them resemble the proceeding in the cylindrical form of the head and body and in the smallness of their scales. The mouth is less dilatable than in other ophidians of this division for the tympanic bone is directly articulated to the cranium while in the last it is suspended to a mastoid bone which is itself movable. The genus of tortoise possesses this kind of organization. In all the ordinary serpents we have yet to mention the mouth is so formed as to enable the animal to swallow bodies larger than itself. The two branches of the lower jaw are not united and the kind of peduncle which sustains them, the tympanic bone is not only movable itself but is suspended to another portion of the temporal bone called mastoid bone which is also separate from the cranium and attached to this bony case by ligaments and muscles only. The branches of the upper jaw are not fixed to the intermaxillary bone except by ligament which permits them to separate more or less. The palantine arches also participate in this mobility. Another character peculiar to this group is the existence of sharp teeth curved backwards planted in these arches as well as in the upper and lower jaws. In other respects the armature of the mouth varies and these differences are of great importance for they coincide with the existence or absence of an apparatus for the secretion of an active poison which the animal uses to kill the prey at bites. Ordinary serpents are therefore divided into venomous serpents and serpents which are not venomous. The non-venomous serpents are recognized by their teeth no one of which is movable or hollowed by a canal or gutter. They are all fixed and they form in the mouth four nearly equal ranges above and two below. Those serpents that have the under part of the body and tail furnished with a single band of transverse scales are described under the name of Boas and we give the collective name of Colibers to those in which the upper part of the tail is covered by plates and pairs divided on a middle line. The division of Boas is composed of Boas properly so-called of Eryx, et cetera. The Boas properly so-called have a compressed body, a prehensile tail, a hook on each side of the anus and small scales on the back of the head at least. The largest serpents known belong to this genus. Certain species attain 30 and even 40 feet in length and manage to swallow deer and as we are assured even oxen. They are unprovided with venom but possessing great agility and prodigious strength they are not the less formidable. Concealed in the grass or suspended by its tail from the branches of a tree in a pathway or on the bank of a rivulet, the Boa watches an opportunity of seizing its prey which it surrounds in its folds and presses so strongly that the animal is soon stifled and its bones crushed. When the serpent has so to speak needed its victim it bathes it and slaver and enormously dilating its jaws slowly swallows it. We are assured that several days are required to swallow an entire animal eaten in this way and that a part of it is already digested before the whole has entered the mouth of the reptile. After a repast of this kind Boas remain motionless and some retired spot exhaling a fetid odor. It is then easy to kill them and it appears their flesh is not a disagreeable element for certain Indian tribes feed upon it. During a very long time the greatest confusion pervaded the history of these great serpents which were confounded with the pythons. It was believed they were found in Africa and Asia as well as in America but it now seems to be certain that they are peculiar to the Western continent. The most celebrated species owes its name to an error of this kind. It was called the Divine Boa because what was said of certain large culibres which the Negroes of Mozambique make objects of religious worship was attributed to it. It seems that the Brazilians and even the ancient Mexicans rendered it similar honors. This enormous reptile which is also called the Boa Constrictor inhabits the warm and humid parts of America. Its head is covered with small scales to the end of the muscle and it is easily recognized by a sort of chain links formed along the back of hexagonal blackish spots and others of a yellowish color. Two other species which inhabit the same countries attain nearly the same size, the Boa Anaconda and the Boa Obama. The division of culibres includes the pythons, the culibres properly so-called and many other genre. The pythons are, as it were, the representatives of the Boas in the old world. They attain the same gigantic size and are also furnished with hooks near the anus. They have narrow ventral plates but those beneath the tail are double instead of being simple. It is to be remarked, however, that some of these serpents have the first, others the second plates of the tail simple which seems to establish a gradual passage betwixt these two genre, the distinction of which, in other respects, is founded upon unimportant particulars. Be it as it may, to the pythons must be referred all that has been said of the Boas of Africa and Asia. The culibres, properly so-called, culibre, have the head covered by large plates and neither faucets on the other sides of the muzzle nor hooks near the anus. The number of these serpents is immense. The most common in France is the ringed snake, culibre natrix. It is ash-colored with black spots along the flanks and three wider spots form a collar around the neck. Its length is about three feet. It is found in the neighborhood of stagnant waters. It swims with ease and lives chiefly on insects, mollusks and frogs. It does not attempt to bite, except when very much irritated and the wound it inflicts is by no means dangerous. It is eaten in many French provinces. Then a miss serpents are provided with a particular gland situate on each side of the head which pours out the poison that it secretes by an excretory duct, the extremity of which empties into one of the maxillary teeth of the upper jaw. This gland is placed beneath the temporal muscles so as to be compressed when they contract and this tooth, which is larger than the others, is sometimes perforated by a canal and at others simply has a gutter on one side. But in either case, its duct is in communication with the excretory canal of the venomous gland and serves to pour the poison into the bottom of the wound made by the tooth itself. This liquid is a most violent poison. It is neither accurate nor burning and only produces a sensation on the tongue analogous to that occasioned by a fatty matter and may be swallowed with impunity. But introduced into a wound in sufficient quantity, it causes death with frightful rapidity. Its energy varies according to the species and according to the condition of the serpent. The same species seems to be more dangerous and warm than in cold or temperate climates and the effects are serious in proportion to the quantity of poison poured into the wound. These animals are more formidable when they have fasted for some time and the poison has accumulated in considerable quantity in the glands where it is secreted than when they have just bitten several times and only a small quantity of the liquid is left. It is remarked also that their poison does not act in the same manner on all animals. It appears that to leeches, snails, the asps, the colobor and the angway, the venom of the viper, for example, is not poisonous while it kills all warm-blooded animals, lizards and the viper itself with great rapidity. In general, the quantity of poison necessary to cause death is all things being equal, large in proportion to the size of the animal wounded. Thus when the hundredth part of a grain of poison of a viper is sufficient to kill a sparrow, it would require six times as much to kill a pigeon. This poison to act on the animal economy must be absorbed and carried into the circulation. Therefore, in cases of bites of venomous serpents, we should hasten by appropriate means to prevent this absorption so as to gain time to extract or destroy the poison deposited at the bottom of the wound. Compression of the veins above the wound, between it and the heart and the application of a cupping glass over the wound itself are the most appropriate means of retarding the absorption of the poison. But to remove all danger completely, we should enlarge the wound and cauterize the bottom of it either with a red-hot iron or with some energetic caustic. Several internal remedies have been much vaunted, such as ammonia or volatile alkali, arsenic, et cetera. But these means, though sometimes useful, should not inspire great confidence. The Indians of South America attribute still greater virtues to a plant of that country, known under the name of guaco or mycania guaco. They assure us that not only the application of the leaves of the guaco to the bite of the most venomous serpents prevents all deleterious effects, but also that inoculation with the juice of this plant prevents these animals from biting persons so prepared. In support of this opinion, the observations of Virgus, a Spanish author, and of Mutus are cited. And the celebrated and learned traveler, Baron Humboldt, thinks, according to some experiments, that the guaco may impart to the skin an odor which is repugnant to the serpents and prevent it from biting. Serpents with movable venomous fangs are the most formidable. The fangs, situate in front of the mouth, are isolated, very sharp, and pierced by a small canal, which opens near their extremity. They're fixed on very small, maxillary bones. And these bones being supported on a long pedicle are very movable, so that when the animal does not wish to use them, they are folded backwards and lie concealed in a fold of the gum. And when required, on the contrary, they are erected. There is one of these teeth on each side, and behind each one there are many germs to replace it in the event of its being broken in a wound. But the intermaxillary bones support no other teeth, and consequently we find in the upper part of the mouth only two rows of palatine teeth instead of four rows as in colobers. The head of these serpents is generally wide behind and their aspect is more fierce than that of the proceeding. They are all ovoviviparis, that is, they are born alive because their eggs are hatched before they are laid. Hence the name of viper, which is a contraction of viviparis, is given to most of them. The most remarkable genre of this division of venomous serpents are the crotalis, trigonosophilus, viper, and naja. The rattlesnakes, crotalis, owe their name to a singular apparatus which terminates the tail and which distinguishes them from all other ophidians. It consists of a series of horny scales loosely fitting into each other like a nest of boxes, which move, vibrate, and sound when the animal moves its tail. The number of these scales increases with age. It seems there is an additional one after each molt and that they are formed by the epidermis of the serpents, turned upon itself like the finger of a glove and retained at the extremity of the tail. This instrument vibrates with extreme rapidity and thus produces a noise sufficiently loud to be heard at a distance of several fathoms. Rattlesnakes attain a length of five or six feet and even more, they inhabit America and are celebrated for the violence of their poison. In general, they do not bite except when provoked and they rarely attack animals too large for them to swallow. Notwithstanding that their food chiefly consists of birds, squirrels, et cetera, they do not climb upon trees. It was believed for a long time that they possess the power of stupefying their victims by their breath or even charming them by their gaze and thus forcing them to enter their mouth. But it is only the extreme terror they inspire in small animals which confounds them so much as to prevent their flight, causing them to perform irregular movements and even to fall into the jaws of their enemy. These serpents ordinarily keep themselves coiled spirally near a watering place frequented by small mammals. There they tranquilly wait until some victim presents itself and when within reach they spring upon it with the rapidity of lightning. In parts of North America where the winter is rigorous they are benumbed during winter and we are assured that during the cold season their bite is not dangerous. In Cayenne and other warm countries they are never benumbed. Negroes eat their flesh. Many species of rattlesnakes are known. Most of them have the head covered with scales like those on the back. That which is most common in the United States is brown with the regular transverse blackish bands. That of Cayenne has lost and shaped spots bordered with black. Both are about six feet in length. The trigonacephalae are distinguished from the proceeding by the absence of the rattle. But like them they have the faucet or pit behind the nostrils. Some of them have simple subcautal plates like the boas and rattlesnakes. Others have the tail furnished beneath with double plates like the coloburs and most vipers. They equal the rattlesnakes and the violence of their poison and most of them inhabit the western continent. The most celebrated species is the yellow trigonacephalus also called the yellow snake of the West Indies and lance headed viper, trigonacephalus lanceolatus. This reptile is very common in Martinique and the neighboring islands. It lives among sugar canes where it feeds on rats and causes the death of many slaves. Its length is from six to seven feet and it is extremely active. It climbs the highest trees in pursuit of its prey and springs like lightning, not only on birds and other small animals upon which it ordinarily feeds but also on large animals and even on man. The vipers, vipera, differ from the venomous serpents just mentioned by the absence of the pits behind the nostrils. Many of them have been frequently confounded with the coloburs on account of their double subcautal plates and some of them having the head furnished with large plates like the latter. But most all vipers have the head covered by small, imbricated or granular scales. The common viper, vipera baris, possesses this latter character. It rarely exceeds two feet in length and is generally brown with a double row of transverse black spots along the back and another row upon the flank. But these spots are often united, forming zigzag bands. One of these vipers is sometimes named the asp in some parts of France but it should not be confounded with the true asp of the ancients. It inhabits the mountainous, stony and woody districts of temperate and southern Europe. It feeds on mice, moles, young birds, reptiles and even insects and worms. During the cold season these reptiles remain benumbed in holes where several are often found twine together. They are most frequently seen on the first fine days of spring, warming themselves in the sunshine. But when the weather becomes very hot they are rarely met. They produce from 12 to 25 young ones at each birth which do not acquire their full size until they are six or seven years old. Of all the venomous reptiles of Europe the common viper is the most dangerous even in the climate of France. Its bite may cause the death of a man in a few hours and kill small animals in a few minutes. The quantity of poison it generally pours into a wound is not sufficient to be fatal to man. The little viper, vipera chersoa, which is common in the north of Europe and which is also found in the Pyrenees has upon the head three plates somewhat larger than the scales surrounding them. It is about six inches long but its poison is very violent. The vipera Illyrica inhabits the south of Europe and is distinguished from the common viper by a small soft horn covered with scales that it has on the end of the muzzle and the horned viper, Cullibur Cerastes on which the ancients often speak is recognized by a small horn placed on each eyebrow. It is found in the burning sands of Egypt and Syria. The Naja are resembling the vipers except that their head is always furnished with plates and the interior ribs can be erected and carried forward so as to dilate this part of the trunk into a kind of disk which is more or less wide. Two species of this genus are known the Spectacle Snake and the Asp of Egypt. The Spectacle Snake or Cobra Capello of the Portuguese in India, Cullibur Naja owes its name to a black line in form of a pair of spectacles traced upon the extensible part of its neck. Its length is about four feet. Its bite is extremely dangerous and it is very fierce. Nevertheless, Indian jugglers teach it to execute certain movements in time to the sound of a flute and employ it to astonish the public. To increase the sale of their pretended specific against the venom of this reptile they permit themselves even to be bitten by the serpent somewhat tamed, however but they take the precaution previously to extract its poisonous fangs. The Asp which inhabits Egypt, Cullibur Haja and which is about two feet long is also employed by the jugglers of those countries to amuse the public by pressing it with the fingers on the back of the neck. They cause it to fall into a sort of catalepsy which renders it stiff and immovable as if they had changed it into a rod or a stick. Its poison is very active and Galen relates that at Alexandria they resorted to the bite of this serpent to abridge the punishment of criminals condemned to death. It is unquestionably the Asp of Cleopatra. The ancient Egyptians took it as the emblem of the protecting divinity of the world and sculptured it on their monuments on opposite sides of a globe. Its habit of erecting itself when approached led them to believe that it watched the fields in which it was found. Other venomous serpents with isolated fangs called elapses have a mouth which is hardly dilatable and there are some in which the tail is compressed in the form of a paddle whose habits are aquatic. They form the genus of Platoris. Among the venomous serpents without isolated fangs there are some which are scarcely distinguishable from the colobers. Their mouth is furnished above with four rows of teeth like the non-venomous serpents without there being perceived in the place ordinarily occupied by the fangs, anything of a nature indicative of the existence of a venomous apparatus. In fact, the excretory canal of the poisonous gland in them terminates in one of the last maxillary teeth which is somewhat larger than the others and simply furrowed by a gutter. Some of the serpents of America and Africa possess this kind of organization. There are also others which with the armature of the mouth very nearly like the last have the first maxillary tooth larger than the others and pierced like the movable fangs above mentioned to conduct the poison. Some known in India under the name of rock serpents have simple plates under the belly and tail and to constitute the genus Bungaris. The others called hydrus have the posterior part of the body and tail very much compressed and raised vertically which gives them facility in swimming. They are common in certain parts of the Indian seas. End of lesson three, part two.