COMPARATIVE ANATOMY. 



parts are nearly of the same length in the 

 orang-outang. Some persons have af- 

 firmeu that the negro forms a connecting 

 link between the European and the 

 orang-outang in these respects. (White, 

 on the regular Gradation in Man and Ani- 

 mals, &c.) In some other simiae the leg 

 and fore-arm exceed the thigh and arm. 

 In other animals, although there are some 

 varieties, the leg is generally longer than 

 the thigh. 



The fibula is consolidated to the tibia 

 at its lower end in the mole and rat. It 

 only exists as a small styloid bone in the 

 horse, and becomes anchylosed to the 

 tibia in an old animal. 



The structure of the metatarsus in the 

 ruminating animals, and the horse, is the 

 same with that of the metacarpus. 



The tarsus of the horse is composed of 

 six bones ; and is the part known in 

 common language by the name of the 

 hock. 



Animals of the genus simia and lemur, 

 instead of having a great toe placed pa- 

 rallel with the others, are furnished with 

 a real thumb : i. e. a part capable of being 

 opposed to the other toes. Hence these 

 animals can neither be called biped nor 

 quadruped, but are really quadrumanous 

 or fourhanded. They are not destined to 

 go either on two or four extremities, but 

 to live in trees, since their four prehen- 

 sile members enable them to climb with 

 the> greatest facility. So that Cuvier has 

 denominated them " les grimpeurs pars 

 excellence. " Lemons d'Anat. Comp. vol. 

 i. p. 493.) The prehensile tail of seve- 

 ral species is a further assistance in this 

 way of life. The opossum, and others of 

 the genus didelphis, have a similar struc- 

 ture with the quadrumajia ; and it an- 

 swers the same purpose. Here, how- 

 ever, there is a separate thumb on the pos- 

 terior extremity only, whence Cuvier 

 calls them pedimanes. 



Man is the only animal in which the 

 whole surface of the foot rests on the 

 ground ; and this circumstance arises 

 from the erect stature, which belongs 

 exclusively to him. In the quadrumana, 

 in the bear, hedge-hog, and shrew, 

 (which are called by Cuvier planti- 

 grades,) the os calcis does not touch 

 the ground. 



The heel of a species of bear belong- 

 ing to this country, viz. the badger (ur- 

 sus meles) is covered with a long fur, 

 which proves that this part cannot rest 

 on the ground ; although the structure 

 both of the bones and muscles of the 

 lower extremity of this animal approach- 

 es considerably to that of man. The 



same fact is stated of the bear itself, 

 properly so called by the Parisian dis- 

 sectors. 



In other animals the body is sup- 

 ported upon the phalanges of the toes, 

 as in the dog and cat ; in the horse and 

 ruminating animals, no part touches the 

 ground but the last phalanx. Here the 

 elongation of the metatarsus removes the 

 os calcis to such a distance from the toe, 

 that it is placed midway between the 

 trunk and hoof. 



S1CELKTON OF BIRDS. 



The skull, which in the adult has no 

 sutures, is articulated to the spine by a 

 single rounded condyle. This structure 

 gives the head a great freedom of motion, 

 particularly in the horizontal direction. 

 It enables the bird to place its bill be- 

 tween the wings when asleep ; a situation 

 in which none of the mammalia can place 

 the snout. 



The lower jaw is articulated to the cra- 

 nium by means of a square bone on each 

 side, called os quadratum. The superior 

 mandible, which is completely immove- 

 able in mammalia, has, with a few excep- 

 tions, more or less motion in birds. It 

 either constitutes a particular bone, dis- 

 tinct from the rest of the cranium, to 

 which it is articulated, as in the psittaci 

 (birds of the parrot kind ;) or it is con- 

 nected into one piece with the cranium, 

 by means of yielding and elastic bony 

 plates ; as is the case with birds in ge- 

 neral. It is quite immoveable in a very 

 few instances, as the tetrao urogallus 

 (cock of the woods) and the rhinoceros 

 bird. 



The jaws are entirely destitute of teeth. 

 The bill may be considered, in some de- 

 gree, as supplying the place of teeth ; 

 yet as none of these animals masticate 

 their food, but swallow it whole, the bill 

 can only be compared to the incisors of 

 such animals as use them for seizing and 

 procuring their food. 



It consists of a horny fibrous matter^ 

 similar to that of the nail, or'of proper 

 horns ; and is moulded to the shape of 

 the bones which constitute the two man- 

 dibles, being formed by a soft vascular 

 substance, covering these bones. Its 

 form and structure are as intimately con- 

 nected with the habits and general cha- 

 racter of the animal, as those of the teeth 

 are in the mammalia. Hence an enume- 

 ration of its different figures and consis- 

 tence belongs property to the department 

 of natural history, where it forms the 

 foundation of classical distinctions. 



