ORDER BATRACHIA. 421 



Although the nerves are very distinct and very robust in 

 the batracians, in proportion to the other organs, the cavity 

 of the cranium which contains their origin is in general very 

 small. The eye is contained in a very large orbit ; it is 

 protected by three lids in some species, and moistened by a 

 fluid analogous to tears. The pupil is very dilatable, usually 

 of a rhomboidal form, elongated, and in a vertical direction. 

 The ear of* these reptiles does not appear externally ; a tym- 

 panic box is found, however, under the skin, and sometimes 

 two osselets of the ear. The nostrils are very simple, carried 

 in front of the muzzle, which they generally cross, and pro- 

 longed into a small membranous tube, in the interior of 

 which is observed a valvule which is intended for respira- 

 tion. The tongue is mucous, adherent to the mouth in the 

 salamanders, and attached to the front of the lower jaw in 

 the tailless batracians. The sensation of touch appears to 

 be perfect in these animals. All have a naked skin, with a 

 mucous epidermis, and often furnished with an assemblage 

 of glands and follicles in the form of warts. Their toes are 

 often more or less cleft, especially on the front feet. 



All the reptiles of this order, when arrived at the perfect 

 state, subsist on living animals, and never on carcases. Their 

 mouth is very wide and without moveable lips ; their teeth, 

 very short, are implanted in the jaws, which appear firmly 

 crenulated. In this same perfect state their intestinal canal 

 is short, and in that same cavity of the belly, are observable 

 a liver with its vesicle, a spleen, an epiploon, kidneys, and a 

 bladder. 



The circulation of the batracians may be regarded as 

 simple ; the heart has but one ventricle and one auricle. A 

 part of the blood passes through the lungs or gills, and then 

 returns into the general torrent ; the lungs float in the cavity 

 of the belly : they are formed of very large cells. Some- 

 times there is but a single one, as is observed in the sala- 



