THE LAST STAGES IN THE GENEALOGY OF MAN. 827 



tion of prehension, but they are at the same time organs of loco- 

 motion; the hinder limbs are also adapted to walking, bnt they 

 are at the same time organs of prehension. With the lemurs 

 there are also the same general types of all the limbs, for pre- 

 hension in front, for walking behind, but the fore extremity is in 

 fact more a i3aw, and the hinder one more a hand by comparison ; 

 witness, for example, the Clieiromys. Other monkeys are as quad- 

 rupedal as they are quadrumanous. Consider the three upper 

 segments of each limb : there are indeed an arm in front and a 

 leg behind ; but look only at the last segment, and it will be found 

 to be, in front as well as behind, a hand in its principal character- 

 istics, the separated and opposable thumb, and the nails. 



With man, the harmony is perfect, because the functions are 

 specialized, and the organs are all adapted in the same respective 

 directions, the fore ones for prehension, the hinder ones for 

 walking. Beyond our branch of the primates, looking toward its 

 origin,, the four limbs all exhibit themselves with the same types, 

 but less affirmed, less precise : all four for prehension, the fore 

 ones more so ; all four for walking, the hinder ones more so. 

 The evolution begins after the train of the marsupials, and spe- 

 cializations are made in different directions. With some, as the 

 .galeopitheci and the cheiropters, the particular adaptation took 

 the direction of flight ; a part or all of the limb was not trans- 

 formed, but bent itself to what was required, was obedient to 

 solicitations. With others, as the ungulates, the adaptation took 

 the direction of an exclusive locomotion upon all four limbs. 

 These became gradually modeled upon the same type, the useless 

 bones disappeared or were fused, and some superfluous motions 

 ceased, while others became accentuated, and the necessary cor- 

 responding anatomical dispositions with them. With others, as 

 the carnivora, which were to run on the ground to reach their 

 prey, while they must be able at the same time to seize, hold, and 

 tear it, the four paws remained perfect locomotor organs, but at 

 the same time also organs of attack by their claws, and to a cer- 

 tain measure, particularly in the fore extremities, organs of pre- 

 hension. An adaptation of another kind was produced with the 

 monkeys. The animals from which they sx)rung dwelt in trees 

 and ran along the branches. They needed to increavse their power 

 of prehension, they had to clasp the rounded trunks of trees, to 

 hook on to branches in passing from one to another. The adap- 

 tation seems to have appeared first in the hinder limbs, and then 

 in the fore-limbs. The whole of the limb did not have to lose its 

 peculiar type for that ; but it was enough if the extremities were 

 in some way fitted to it. Nature was contented with nails, sepa- 

 rated and opposable thumbs, and more flexible fingers, without 

 going up to the next segment. 



