230 L. Manouvrier — Pithecanthropus erectus. 



that this was an ancestor of man, it is necessary to find now 

 an ancestor to this Pithecanthropus, and it seems requisite 

 that this ancestor be not inferior to existing anthropoids. It 

 must have been capable of adopting, in case of need, the up- 

 right position, and been led, by its conformation, to take that 

 attitude rather than the quadruped attitude. Such would be 

 certainly the case with all known anthropoids, all of which 

 are veritable biped climbers. 



Let us recall here the existence in the Miocene epoch of 

 several anthropoid species such as the Dryopithecus, the 

 Pliopithecus, and the Anthropopithecus sivalensis. As Mr. 

 Dubois has remarked, his species does not lack for ancestry. 



The transformation of the habitual mode of locomotion may 

 have been very rapid, but the consecutive, morphologic trans- 

 formations must have demanded much time and cannot have 

 been fixed hereditarily until after a certain number of genera- 

 tions — hundreds perhaps, and perhaps many less, for selection 

 under the conditions indicated above may have been very 

 active ; the two sexes must have contributed actively to the 

 progression, and the young must have imitated their parents 

 with an ever-increasing facility. As regards the direct mor- 

 phologic consequences of the change of attitude, we may 

 suppose they were produced with great rapidity, if we are to 

 judge from the multiple skeletal variations caused in man 

 under the influence of the minimum of functional variations 

 compared with those with which we have to do here. 



As regards cerebral increase, it proceeds with such slowness 

 that we can scarcely affirm the fact has been established at all 

 for our European races since prehistoric times. But the cra- 

 nial capacity of the Pithecanthropus surpassed by about 300 

 grams that of the largest gorillas. It surpassed by at least as 

 much that of its ancestor gibbon s, if this latter was of the 

 same stature as the Pithecanthropus. There is here an enor- 

 mous difference, greater than that between the average for our 

 lowest and the average for our highest existing human races. 

 It is not, however, embarrassing for the hypothesis under dis- 

 cussion. 



We must consider, in fact, that the human species has never 

 realized, since the beginning of its existence, a progress com- 

 parable to that represented by the passage from the state of 

 climber to the state of "marcheur bipede." This passage 

 represents a veritable liberation of the superior members, the 

 hands, previously employed as organs of locomotion the same 

 as the feet. It is by the mode of locomotion of the climber 

 that the hand became, little by little, apt for the function of 

 prehension, then for the function of manipulation, and it is by 

 virtue of the complete emancipation here supposed of the 



