Classification of the Mammalia. 61 



The human foot is broad, plantigrade, with the sole not invert- 

 ed as in Quadrumana, but applied flat to the ground ; the leg 

 bears vertically on the foot; the heel is expanded beneath ; the' 

 toes are short, but with the innermost longer and much larger 

 than the rest, forming a ' hallux' or great toe, which is placed on 

 the same line with, and cannot be opposed to, the other toes ;the 

 pelvis is short, broad, and wide, keeping well apart the thighs ; 

 and the neck of the femur is long, and forms an open angle with 

 the shaft, increasing the basis of support for the trunk. The whole 

 vertebral column, with its slight alternate curves, and the well, 

 poised, short, but capacious subglobular skull, are in like harmony 

 with the requirements of the erect position. The widely-sepa- 

 rated shoulders, with broad scapulas and complete clavicles, give 

 a favourable position to the upper limbs, now liberated from the 

 service of locomotion, with complex joints for rotatory as well as 

 flexile movements, and terminated by a hand of matchless perfection 

 of structure, the fit instrument for executing the behests of a ra- 

 tional intelligence and a free will. Hereby, though naked, Man 

 can clothe himself, and rival all native vestments in warmth and 

 beauty ; though defenceless, Man can arm himself with every variety 

 of weapon, and become the most terribly destructive of animals. 

 Thus he fulfils his destiny as the supreme master of this earth, 

 and of the lower Creation. 



In these endeavours to comprehend how Nature has associated 

 together her mammalian forms, the weary student quits his task 

 with a conviction that, after all, he has been rewarded with but 

 an imperfect view of such natural association. The mammalian 

 class has existed, probably from the triassic, certainly from the 

 lower olitic period ; and has changed its generic and specific 

 forms more than once in the long lapse of ages, during which life- 

 work has been transacted on this planet by animals of that high, 

 grade of organization. Not any of the mammalian genera of the 

 secondary periods occur in the tertiary ones. No genus found in 

 the older eocenes (plastic and septarial clays, &c.) has been dis- 

 covered in the newer eocenes. Extiemely few eocene genera occur 

 in miocene strata, and none in the pliocene. Many miocene ge- 

 nera of Mammalia are peculiar to that division of the tertiary 

 series. Species indistinguishable from existing ones begin to ap- 

 pear only in the newer pliocene beds. Whilst some groups, as 

 e. g. the Perissodactyles and omnivorous Artiodactyles, have been 

 gradually dying out, other groups, as e. g. the true Ruminants, 

 have been augmenting in genera and species. 



