CHAPTER XXII. Functions and Instincts. Reptiles. IN the whole sphere of animals, there are none, that, from the earliest ages have been more abhorred and abominated, and more repudiated as unclean and hateful creatures, than the majority of the class we are next to enter upon,-that of Reptiles. One Order1 of them, indeed, consisting of the turtles and tortoises, and some individuals belonging to another, are exempted from this sentence, and are regarded with more favourable eyes; but the rest either disgusts us by their aspect, or terrify us by their supposed or real powers of injury. In Scripture, the serpent; the larger Saurians, under the names of the dragon and leviathan; and frogs are employed as symbols of the evil spirit, of tyrants and persecutors, and of the false prophets that incite them.3 Yet these animals exhibit several extraordinary characters and qualities. They are endued with a degree of vivaciousness that no others possess, they can endure dismemberments and privations which would expel the vital principal from any creature in existence, except themselves. Their life is not so eoncentrated in the brain, which with them is extremely minute but seems more expanded over the whole of their nervous system: take out their brain or their heart, and cut of their head, yet they can still move, and the heart will even beat many hours after extraction; it is also stated that they can live without food for months, and even years.* But though gifted by their Creator with such a tenacity of life, yet is that life often raised a very few degrees above death. Many of them select for their retreats damp and gloomy caverns and vaults, shut out from the access of the light and air. In allusion to this circumstance, Babylon, the imperial city, she, who in ancient times subjected the eastern world to her 1 The Chelonians. 2 The Gecko, Monitor, Chamæleon, &c. amongst the Saurians. 3 Job, xli. 34; Psl. xxvii. 1 ; Ezek. xxv. 3; Rev. xx. 2, xvi. 13. 4 Cuv. Regn. An. ii. 1. 8. Lacep. Quad. Ovipar. i. 20. domination, was forewarned that she should become heaps, and a direlling-place for dragons.1 Whether the many instances that have been recorded in different countries, of toads found incarcerated alive in blocks of stone or marble, or in trunks of trees, are all to be accounted for by supposing a want of accurate observation of the concomitant circumstances in those that witnessed their discovery, I will not take upon me to say; but they are so numerous, as to leave some doubt upon the mind whether some of these creatures may not have been accidentally interred alive, as it were, when in a torpid state, and continued so, till, their grave being opened, and the air admitted to their lungs again, their vital functions have been resumed, to the astonishment of those who witnessed the seeming miracle. Though so given to withdraw themselves into dark and dismal retreats, yet many of them are fond also of basking in the sun-beam, particularly the serpents and the lizards. Zoologists seem not even yet fully to have made up their minds with regard to the classification of Reptiles. Linné placed them in the same Class with the Cartilaginous Fishes, of which they form his first and second Orders; but subsequent zoologists, with great propriety, have generally considered them as forming a Class by themselves, under their primeval name of Reptiles. This Class M. Brongniart divided into four Orders, viz. Chelonians, Saurians, Ophidians and Batrachians: and Baron Cuvier has followed this arrangement in his Règne Animal. Latreille, adopting the Group, has divided it into two Classes, Reptiles and Amphibians. The Reptiles he considers as forming two Sub-classes, viz. Cataphracta, containing the Chelonians, and Crocodiles, and Squamosa, containing the remaining Saurians and the Ophidians. His second Class, the Amphibians, consisting of the Batrachians of Brongniart, with the addition of the Proteus, Siren, &c. he divides into two Tribes, viz. Caducibranchia, or the proper Batrachians, and Perennibranchia, or the Proteus, Siren, Axolot, &c. This classification is adopted by Dr. Grant, except that he does not subdivide the Reptiles into two Sub-classes; and Latreille's two Tribes of Amphibians he properly denominates Orders. That Reptiles, in the larger sense of the term, form a natural Group, will be generally admitted, when it is considered that the salamanders, or naked efts, evidently connect the Batrachians with the Saurians, and were formerly considered as 1 Jerem. li. 37. 3 Outlines of a Course of Lectures, &c. 14-16. 2 Amphibia. a kind of lizard; it seems to me therefore more consistent with nature to consider the Reptiles as forming a single Class. This opinion has received strong confirmation from a circumstance communicated to me by my kind friend Mr. Owen, well known as one of our most eminent comparative anatomists. In a letter received from him, since I wrote the preceding paragraph, in reply to some queries I had addressed to him, he says, "I lose no time in replying to your very welcome let ter, because I have a statement to make which justifies your disinclination to regard the Reptilia of Cuvier as including two distinct Classes. Not any of the Batrachia have a single auricle; for though the venous division of the heart has a simple exterior, it is in reality divided internally into two separate auricles, receiving respectively, the one, the carbonized blood of the general system, the other and smaller, the aërated, or vital, blood from the lungs. This I have found to be the case successively in the frog and toad, the salamander and newt, and lastly, in the lowest of the true Amphibia, the Siren lacertina, which in its persistent external branchiæ comes nearest, I apprehend, to the Fishes." By this statement it appears that those characters, which have been deemed sufficient to warrant the division of the Reptiles into two distinct Classes, exist only in appearance. I shall consider them therefore as forming only one, of which the following seem to constitute the principal diagnostics. REPTILIA. (Reptiles.) Animal, vertebrated, oviparous, or ovoviviparous. Eggs, hatched without incubation. Heart, really biauriculate, though in some the auricles are not externally divided. Blood, red, partially oxygenated, cold. Brain, very small; vitality, in some degree, independent of it. Integument, various. As the two Orders into which the Batrachians of Cuvier are divided by Dr. Grant, differ from the rest of the Class not only in their respiratory organs, but also in other important particu lars, indicating that they form a group of greater value than the other three Cuverian Orders, I shall therefore consider the Class of Reptiles as further divided into two Sub-classes, which I propose to denominate, from the difference of their integument, Malacoderma and Scleroderma. Sub-class 1.-Reptilia Malacoderma. (Soft-coated Reptiles.) Heart, with two auricles, externally simple, but internally divided. Integument, soft, naked. Eggs, impregnated, after ex trusion. This Sub-class consists of the two orders called, by Latreille and Dr. Grant, as above stated, Caducibranchia and Perennibranchia; but considering the Reptiles as forming a single Class, for the sake of concinnity of nomenclature, I think it would be better to restore to the first their old name of Batrachians; and, as the animals that form the second, as Cuvier observes, are the only true Amphibians,1 to distinguish them by the name that strictly belongs to them alone. Sub-class 2.-Reptilia Scleroderma. (Hard-coated Reptiles.) Heart, with two auricles. Integument, hard, often scaly. Eggs, impregnated before extrusion. SUB-CLASS 1. 1. Amphibians. 2. Batrachians. ORDERS. SUB-CLASS 2. 3. Ophidians. 5. Chelonians. Order 1.-Amphibians. (Siren, Proteus, Axolot, &c.) Respiration, double, by gills in the water, and by pulmonary sacs in the air. Gills, permanent. Legs, 2-4. Order 2.-Batrachians. (Amphiuma, Triton or Water-newt, Salamander, Toad, Frog, &c.) Respiration, at first by gills, and afterwards by lungs. Gills, temporary. Ribs, rudimental. Legs, four. Undergoes a metamorphosis. Order 3.-Ophidians. (Snakes and Serpents.) Body, covered with scales, without legs. Ribs, movable. Mouth, armed with teeth. Cast their skin. Order 4.-Saurians. (Two-footed and four-footed Lizards, of various kinds; Crocodiles, Alligators, &c.) Body, covered with scales, or scaly grains, terminating in a tail. Ribs, moveable; mouth, armed with teeth. Legs, 2-4. Order 5.-Chelonians. (Turtles and Tortoises.) Body, protected above by a carapace, or shield, formed by the ribs, and below by a plastron, or dilated sternum. Mouth, without teeth. Mandibles, rostriform. Legs or paddles, four. Though the Malacoderm, of soft-coated Reptiles, appear the 1 Règne. Anim. ii, 117. legitimate successors of the Fishes, yet there are some others in the higher Orders that seem to lead off towards them also, for the Ophidians and Apod fishes evidently tend towards each other. The Cæcilia, or blind serpent, too, is almost uniauriculate, and has only some transverse rows of scales between the wrinkles of its skin.1 From this statement, it seems that the Class of Reptiles is connected with the Fishes, not by those at the top of the latter Class, but by those at its base; with the Osseans by the Apods, and with the Cartilagineans by the Cyclostomes; so that they may be almost regarded as forming a parallel line with them, instead of succeeding them in the same series. Even the proper Batrachians seem to tend to the Chelonians, while the Salamanders look to the Saurians. The great body of the Class are predaceous, subsisting upon various small animals, especially insects, and some Ophidians upon large ones; but the Chelonians seem principally to derive their nutriment from marine and other vegetables, though some of these will devour Molluscans, worms, and small reptiles; the Trionyx ferox will attack and master even aquatic birds. Cuvier says, after Catesby, that the common Iguana subsists upon fruit, grain, and leaves. Bosc states that it lives principally upon insects; and that it often descends from the trees after earth-worms and small reptiles, which it swallows whole." Order 1.-The Siren, or Mud-iguana, occupies the first place. in this Order, and seems to connect with the Apod and Cyclostomous Fishes, from which it is distinguished by its gills in three tufts, and by having only one pair of legs. It appears to be an animal useful to man, since it is stated to frequent marshes, in Carolina, in which rice is cultivated, where it subsists upon earth-worms, insects, and other similar noxious crea tures. But of all the animals which God hath created to work his will, as far as they are known to us, none is more remarkable, both for its situation and many of its characters, than one to which I have before adverted, as affording some proof, that the waters under the earth, and other subterranean cavities, may have their peculiar population. The animal I allude to is the Proteus, belonging to the present Order, which was first found thrown up by subterranean waters in Carniola, as we are informed by the late Sir H. Davy, by Baron Zöis. Sir Hum 1 Règne Anim. ii. 99. See above, p. 19. 3 2 Règne An. ii. 44. N. D. D'H. N. xvi. 113. 4 Consolat. in Trav. 187. |
