240 



MAMMALIA. 



Fig. 60. 



Fig. 61. 



Fig. 62. 



Hind extremity, Ape. 

 Fig. 64. 



Hind extremity, Lion. 



Fig. 65. 



Skull of a Rodent, 



Hind ley, Antelope. 



fluences their dexterity, and gives variety to 

 their modes of action : it is the faculty of 

 opposing a thumb to the other ringers, so as 

 to seize the smallest objects, which constitutes 

 a hand, properly so called. This faculty is 

 carried to its highest degree of perfection in 

 man, in whom the whole anterior extremity is 

 free, and can be exclusively employed in pre- 

 hension. These different combinations, which 

 strictly determine the nature of the several mam- 

 miferous animals, have formed the grounds for 

 their distribution into the following Orders. 



" Amongst the Unguiculate animals, the 

 first is MAN, who, in addition to his peculiar 

 privileges in every other respect, is distinguished 

 zoologically by possessing hands on the ante- 

 rior extremities alone ; the posterior extremities 

 being destined to sustain him in the erect 

 position. (Fig. 60.) 



" The Order which comes nearest to Man, 

 that termed Quadrumana, has hands on the 

 four extremities. (Fig. 61.) 



" Another Order, termed Carnivora, has not 

 the thumb free and opposable on either the 

 anterior or posterior extremities. (Fig. 62.) 



" These three Orders possess likewise seve- 

 rally the three kinds of teeth, viz. molars, lani- 

 aries, and incisors. 



" The quadrupeds of the fourth Order, viz. 

 the Rodent ia, have the digits differing little from 

 those of the Carnivora ; but they want the 

 laniary teeth, and have the incisors of a form 

 and disposition altogether peculiar to them- 

 selves. (Fig. 63.) 



" To these succeed the animals whose digits 

 now become much cramped, being sunk deep 

 in large and, most commonly, crooked claws. 

 They are further defective in the absence of 



Skull of the Giraffe. 



incisor teeth ; some of them even want the 

 laniaries, and others are altogether destitute of 

 dentary organs. We shall comprehend them 

 under the term Edentata. (See Jig. 33, vol. ii. 

 p. 49.) 



" This distribution of unguiculate animals 

 would be perfect, and would form a very regu- 

 lar chain, if New Holland had not lately 

 furnished us with a small collateral chain, 

 composed of the Marsupial animals, all the 

 genera of which, while they are connected by 

 a general similarity of organization, at the same 

 time correspond in their dentition* and diet, 

 some to the Carnivora, others to the Rodent ia, 

 and a third tribe to the Edentata. 



" The Ungulate animals are less numerous, 

 and present fewer variations of form. 



" The Ruminantia, by their cloven feet, 

 (fig 64,) their want of upper incisors, (fig. 65,) 

 and their complicated stomach, form a very 

 distinct Order. 



" All the other quadrupeds with hoofs might 

 be united into a single Order, which I would 

 call Pachydermata or Junienta, (fig. 66,) the 

 elephant excepted, which might form an Order 

 of itself, having some remote affinities to the 

 Order Rodentia. The Pachyderms have com- 

 monly incisors in the upper as well as the lower 

 jaw. (Fig. 67.) 



" Last of all come the Mammalia which 

 have no hinder extremities, and whose fish-like 

 form and aquatic life would induce us to form 

 them into a separate Class, if their oeconomy 



* In the article MARSUPIALIA it will be shown how 

 much more essential are the points of resemblance 



between the dentition of the different Marsupial 

 animals than between any of these and the pla- 

 cental genera, with which they correspond in diet. 



