DISTRIBUTION OF MAMMALIA IN TIME. 607 



gression. The thumb is opposable, and the hands are pre- 

 hensile, the fingers being provided with nails. The toes of the 

 hind-limb are also furnished with nails, but the hallux is not 

 opposable to the other digits, and the feet are therefore useless 

 as organs of prehension. The foot is broad and plantigrade, 

 and the whole sole is applied to the ground in walking. 



The dentition consists of thirty-two teeth, and these form a 

 nearly even and uninterrupted series, without any interval or 

 diastema. The dental formula is — • 



. 2 — 2 I — I 2 — 2 3 — 3 



The brain is more largely developed and more abundantly 

 furnished with large and deep convolutions than is the case 

 with any other Mammal. The mammse are pectoral, and the 

 placenta is discoidal and deciduate. 



Man is the only terrestrial Mammal in which the body is 

 not provided with a covering of hair. 



The zoological or anatomical distinctions between Man and 

 the other Mammals are thus seen to be of no very striking 

 nature, and certainly of themselves would not entitle us to 

 consider Man as forming more than a distinct order. When, 

 however, we take into account the vast and illimitable /jy^r/^zW 

 differences, both intellectual and moral — differences which 

 must entail corresponding structural distinctions — between 

 Man and the highest Quadrumana, it becomes a question 

 whether the group Bimana should not have the value of a 

 distinct sub-kingdom ; whilst there can be little hesitation in 

 giving Man, at any rate, a class to himself. At any rate, man's 

 psychical peculiarities are as much an integral portion, or 

 more, of his totality, as are his physical characters, and, as 

 Dr Pritchard says, — " The sentiments, feelings, sympathies, 

 internal consciousness, and mind, and the habitudes of mind 

 and action thence resulting, are the real and essential character- 

 istics of humanity." 



CHAPTER LXXXV. 



DISTRIBUTION OF MAMMALIA IN TIME. 



As a matter of course, the remains of Mammals are scanty, 

 and occupy but a small space in the geological record, since 

 the greater number of the Mammalia are terrestrial, and . the 



