83 APPENDIX. 



the human subject. The coverings of the brain, and 

 the ganglions, and peculiarities of the nerves, are an- 

 nexed. The organs of sense are arranged in the or- 

 der of their simplicity, beginning with that of touch, 

 which is only a villous vascular surface, the villi very 

 short, where the impression is to be made through a 

 thin cuticle, or in the human finger ; very long where 

 the covering is thick, as in the hoof of the horse. 

 The organ of taste is only a modification of the or- 

 gan of touch, and therefore nothing in the organiza- 

 tion is different ; but the varieties in structure adapt- 

 ing the tongue for different purposes are numerous. 

 In many animals it serves the purposes of a hand, 

 to bring the food to the mouth, as in many shell- 

 fish, the ant, bear, woodpecker, and chameleon. Con- 

 nected with the tongue are the fauces, which in many 

 animals have peculiarities. In the electric eel, they 

 have a very curious carunculated appearance ; but 

 they are yet more extraordinary in the camel, which 

 has an apparatus to moisten the parts, so as to pre- 

 vent the painful sensation of thirst, thus adapting it 

 to the sandy deserts which it is destined to inhabit. 

 This apparatus consists of a large bag hanging down 

 several inches in the fauces, and attached to the 

 palate, which the animal can at pleasure move up 

 and down, and lubricate the fauces. The organ of 

 smell is variously constructed, and is more compli- 

 cated in many animals than in man, as in the lion 

 and sea-cow. The organ of hearing in fish consists 

 of three semicircular canals, but is much more com- 



