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557 



the longer that the animal can resist, it receives the 

 greater injury from the change of state, and, conse- 

 quently, has the less chance of awakening to life ; 

 in as far as evidence on such a subject can be col- 

 lected, we believe it may be said that the first symp- 

 tom of a fatal nature, which occurs to those who 

 perish in the snow, or are recovered when they have 

 nearly perished, is a heavy sleepiness, from which 

 they become at last quite unable to keep themselves 

 awake. If only a small portion of the body is ex- 

 posed to this extremity of cold, while the rest of it is 

 kept comparatively warm, then the action on that 

 part becomes a topical disease, which ends in the 

 destruction of the part. This resistance in the whole 

 or part of the body is clearly owing to the natural 

 elasticity of the membranous tissue, which cannot, 

 without long and severe action of the cold, be made 

 to contract the vessels, so as to stop the circulation. 

 In reptiles the necessary vascular constriction is pro- 

 duced by a very slight degree of cold ; and thus they 

 are not in the .least injured by it. Several of the 

 mammalia also hybernate, of which the bats are, 

 perhaps, the most remarkable instance ; for in cold 

 countries they disappear for nearly as long a period 

 of the year as reptiles do in temperate ones. 



When there is little or no difference of seasons all 

 the year round, there is no necessity for the hyber- 

 nation of reptiles ; but whenever there begins to be 

 a perceptible difference, hibernation is sure to occur. 

 In North America the reptiles hybernate as far to 

 the southward as the shore of the gulf of Mexico, 

 though some part at least of the vegetation there is 

 of a tropical character. 



Each species seeks a peculiar retreat in which to 

 pass the season of temporary death. The aquatic 

 Cheloma bury themselves in the mud ; and the land 

 ones in the earth, the crocodiles bury themselves in 

 the sand or other banks ; and the Batrachia hide 

 themselves in holes, or seek the mud under water. 

 The progress of this is gentle and gradual ; but the 

 state itself, however, in the severe weather, very com- 

 plete. Nothing will rouse them but the application 

 of heat ; and that application must be gradual, other- 

 wise the consequences are injurious, if not fatal. 

 While they are in the depth of their hibernation, 

 the suspension of all the animal powers is as total, 

 though of course not so final, as if they were dead. 

 No mechanical action and none of the ordinary che- 

 mical actions have any effect upon them. They may 

 be torn, cut to pieces, burnt with acids, or acted upon 

 in various other ways, without showing, by motion or 

 in any other way, that they have the least feeling of 

 what is done to them. Whether, by unequal expo- 

 sure to the cold, which many of them must expe- 

 rience, particulitr members of their bodies are liable 

 to suffer, as certain parts of the human body do when 

 they are frost-bitten, has not been very clearly as- 

 certained ; but it is probable, and may be at least oue 

 of the uses of that reproduction of parts with which 

 they are endowed. We believe that a seasonal state 

 of dormancy takes place in all or in most reptiles, 

 whatever be the temperature of the country in which 

 they are found, and that it is, in all cases, a total 

 repose, not attended with the slightest diminution of 

 the weight or impairing of the strength of the ani- 

 mal. When the proper action of external nature 

 comes round they again gradually awaken, and re- 

 sume all their functions as if nothing had been the 

 matter, but rather us if they were refreshed by a 



sound and long-continued sleep. As this seasonal 

 repose, which reptiles enjoy, is complete rest to the 

 whole of their system, whereas the sleep of other 

 animals is rest to the system of sensation only, and 

 not to the vital system, the reptile has the advantage 

 of the other animals, and awakens much in the same 

 condition as a creature actually new. 



What we have stated are the leading facts in the 

 structure and more general habits and action of the 

 three orders to which our consideration has been 

 directed. Though they vary much from each other, 

 and cannot be said to follow any one class and pre- 

 cede another, in anything like a regular chain of 

 being, yet they follow the general type of the quadru- 

 ped, or animal with four limbs, to whatever purpose 

 those limbs may be applied, until it appears to merge 

 in the type of the fish, in which class the form is gra- 

 dually obliterated. 



Having done this, we shall now very briefly notice 

 the remaining order, the Ophidia, or snakes and ser- 

 pents, which do not properly range with the others 

 in the structure of their bodies, although they clearly 

 belong to the class of reptiles. They stand in the 

 same anomalous relation to the general class of rep- 

 tiles as the marsupial animals do to the common 

 mammalia, only the anomaly in these is in the mode 

 of reproduction, while in the serpents it is in the 

 general structure of the body. There is another 

 circumstance worthy of notice before we proceed to 

 the outlines of the structure ; and that is, that most 

 of the serpents, which retain within the integuments 

 slight rudiments of extremities, chiefly of anterior 

 ones, the mode of production is simply oviparous, 

 like that of the Sauna, while in the poisonous ser- 

 pents it is ovoviviparous, as it is in the case of the 

 salamander among the batrachian reptiles ; but there 

 are none of the Qphidia which have the same mode 

 of reproduction as the more typical Batrachia, the 

 common frog, for instance. 



To detail the general form of a serpent would be 

 superfluous. It consists of a head, a body, and a 

 tail in one lengthened bone without any extremi- 

 ties, though there are sometimes membranes to the 

 head or neck, which admit of being inflated at the 

 pleasure of the animal, which inflations appear to 

 answer a purpose in the economy of the animals 

 having them, to which we shall have occasion to 

 revert. 



The skeleton is simple in them, consisting chiefly 

 of the skull, the spinal column, and the bones of the 

 head. The skull is small, as in the other reptiles, and 

 the brain is also small and very imperfectly developed, 

 so that the idea of a serpent of any kind being the 

 emblem of wisdom or cunning is without foundation 

 in the nature of the animal. The mouth is the chief 

 organ for taking the food in all serpents ; and it may, 

 in every case, be considered as a prehensile instru- 

 ment, and not a killing or wounding one. The bite 

 of a serpent, considered merely as a mechanical ope- 

 ration, cannot be regarded as very formidable, even 

 in the case of the largest and most powerful of the 

 order, though the action of the poison-fangs, which is 

 a mere puncture and not a bite, not necessarily draw- 

 ing blood, is often of the most deadly character, and 

 it is at all times painful and dangerous, especially if 

 the animal upon which it is inflicted has a diseased 

 habit of body. 



The mouth being thus a seizing and swallowing 

 mouth, and not in any respect a mechanically wound- 



