It E P T 1 L E. 



the sternum, jointly; and in the Batrackia,Vi\i\c\\ have- 

 no ribs, the abdominal muscles and the integuments 

 perform the same office. The Chelonia do not appear 

 to have any other way of taking air into the lungs 

 than by forcibly swallowing it, because they have no 

 part in which the mere pressure of the atmosphere 

 can make a cavity for itself, and therefore they are 

 really the animals which should be called aigou/cvents, 

 or " wind-swallowers," the name which the French 

 give to the goat-suckers, which are capable of getting 

 all the wind they want without any effort in the 

 swallowing of it. 



The voice and the temperature of animals both 

 depend on the respiration, though the voice is modi- 

 fied by the larynx. In reptiles that organ is simple, 

 without any epiglottis, though with various ligaments 

 and muscles to the glottis; and in some, the males of 

 the bull-frogs especially, there are membranous bags 

 and cheek-pouches, that serve further to modify the 

 sound. The loudness of the voice depends on the 

 force with which the animal can expel the air ; and 

 as the crocodiles can do this with far more force than 

 any of the others, they roar or bellow loudly, and 

 often in the most tremendous key. The Chelonia 

 have no such power of respiration, and thus their 

 sounds arc only hissintr and sighing, and these not 

 very often repeated. Some of the land Sauna utter 

 a sort of siftling whistle ; while a few, as, for instance, 

 the common green lizard, have little or no voice of 

 any kind. 



As to the heat of the animals, it cannot be great, 

 because the heat is in proportion to the action of 

 the system only. Most of them, however, keep their 

 temperature a little above the average of the atmo- 

 sphere in which they live. They are all very- soon 

 affected by cold, but many of them can bear a pretty 

 high temperature : not that there is any salamander, 

 which, like the fabled reptile of the ancients, can live 

 in the fire, and there only ; but there are aquatic 

 reptiles in some springs of pretty high temperature. 

 This endurance of heat is not universal, however ; 

 for the common frog cannot live in water so warm as 

 the blood of a healthy human body. The change of 

 temperature which takes place during the paroxysms 

 of excessive activity, in those which can be power- 

 fully excited, has not been examined ; and yet it is 

 a point the settling of which would be of much use 

 in clearing 'up the doctrine of animal heat, about 

 which there are still many things not quite satisfac- 

 tory, notwithstanding all the theories that have been 

 prepared, and all the words that have been written 

 about it. 



Closely connected with the vital system in reptiles 

 is their power of passive endurance, and that of 

 reproducing lost members. The first of these is of 

 no inconsiderable value in throwing light on the 

 relation between the laws of dead matter and the 

 laws of animal life ; and it is not a little satisfactory 

 that the peculiarities of reptiles in this way extend to 

 chemical action as well as to the action of mere 

 temperature. Analogy would lead us to conclude 

 that this ought to be the case ; but a conclusion 

 from analogy is always more satisfactory when we 

 can substantiate it by direct evidence. 



We must not understand that it is in its yielding 

 to'the general laws of nature, that an animal suffers 

 injury, disease, or death, from those laws, but exactly 

 the reverse. For, if an animal could be so formed as 

 instantly, and without effort or resistance, to obey all 



those laws in all their changes, they could have no 

 injurious effect upon it. The only instances which 

 we have, even of inanimate matter, as in perfect 

 obedience to these laws, is in the celestial bodies ; 

 and as there is no resistance to the law there, there 

 is no casualty. The sun is not an atom exhausted 

 by its shining, neither is the planet fatigued by its 

 career in its orbit ; and could there be any such per- 

 fect obedience in terrestrial nature, the thing or 

 being possessed of it, or yielding it, would be totally 

 exempted from death and dissolution. This cannot, 

 however, be the case ; because the law of gravitation 

 to the earth always comes in, claiming and forcibly 

 taking a portion of this obedience ; and therefore 

 the obedience to no other law, whether of matter as 

 such, or of life, can be perfect. Perfect exemption 

 from these laws has of course the same element of 

 permanence in it as perfect obedience to them ; and 

 this is the reason why the immortality of the mind of 

 man is so clear in itself, and in such beautiful harmony 

 with the whole system of nature. 



Life is, in its very essence, an opposing of the 

 common laws of matter, whether mechanical or che- 

 mical ; because the action of life consists in taking a 

 certain quantity of matter from the common stock, 

 and applying it for a longer or a shorter time to the 

 purposes of the animal. It follows from this, by very 

 obvious and even necessary consequence, that the 

 more stubbornly the animal keeps the uniform tenor 

 of its own economy, the more sturdily must it have to 

 battle with the changes which take place in physical 

 nature. We have a remarkable instance of this in 

 the human body, which, as it is adapted to the greatest 

 number of purposes, we ought perhaps to consider 

 as the very chcj '-(Tee uvre of animated matter. But, 

 though the human body can endure a greater range 

 of temperature than the bodies of most animate, there 

 is no question that it does so with a hard struggle, 

 and in all probability it could not do so were it not 

 supported and buoyed up by mental resource. It is 

 incalculable to what an extent the mental hope sus- 

 tains the corporeal frailty ; for we find that, even 

 under the most favourable physical circumstances, 

 if hope becomes extinct, the extinction of life follows 

 close upon it ; and if the body will not die, the agony 

 of the mind makes it lay violent hands upon itself. 

 Yet, notwithstanding all this, and all the resources 

 which the mental sagacity of man open up for him, 

 he is more subject to disease than any other animal. 

 Not only this ; for man is exceedingly liable to be 

 injured by the chemical laws of nature, and is much 

 more easily deranged or poisoned than any other 

 animal of the same size. 



The other animals have none of this mental hope 

 to buoy them up, and therefore they stand upon less 

 advantageous ground, with reference to the changes 

 of physical nature, than man does. It may be thought 

 that their exemption from mental fear is an ade- 

 quate compensation, but it is not ; for, though there 

 are a few timid individuals of the human race who 

 go about mourning and apprehending all the days of 

 their lives, even when they are in the fullest enjoy- 

 ment of the bounty of Heaven, and grumbling is of 

 course the blackest and most criminal of all ingrati- 

 tude ; yet they are the very few, and not the many, 

 the casual exception, and not the habitual rule. So 

 that, upon the fair and philosophic principle, the 

 irrational animals are in much worse condition for 

 battling with the laws of physical nature than man 



