366 POPULAR SCIENCE MONTHLY. 



much brain surface as the anthropoid ape. Applying this test to the 

 human protot3^pe, we find that Pithecanthropus occupies an inter- 

 mediate position between the higher apes and modern man. That is to 

 say: if we set specimen anthropoid skulls in an ascending series ac- 

 cording to cranial capacity, we shall discover that between the higher 

 apes and Pithecanthropus there is a considerable gap; Pithecanthropus 

 is followed shortly in the scale by the Neanderthal group of men, 

 whose skulls were found in the quaternary deposits of Europe; these 

 in turn are succeeded by the crania of the lowest living savages; and 

 from this point the series runs on without interruption through the 

 various races of man to the highest existing types. Thus on the human 

 side there is practically no break in the gradual development of cranial 

 capacity from tertiary to quaternary, and upwards through prehistoric 

 to historic man. The only interval that occurs is on the animal side, 

 between the lowest type of man and the highest type of ape; from 

 which we may infer that the pliocene precursor stood considerably above 

 his simian relatives in intellectual capacity, though the difference was 

 merely one of degree. 



The same result is reached by a comparative study of the convolu- 

 tions of the brain. It has been demonstrated that the gyri of the 

 brains of man and the anthropoid apes are similar, with the exception 

 of the convolutions which enter into the formation of the frontal 

 lobes. The superior and middle gyri of these lobes are much shorter 

 in the brains of anthropoid apes than they are in the brains of man, 

 and in the brains of anthropoid apes the inferior frontal gyri only 

 exist in rudimentary form. These anterior lobes of the brain, or more 

 exactly their cortical nerve elements, to a large extent control the 

 higher intellectual faculties. The condition of these frontal convolu- 

 tions is, therefore, like cranial capacity, an index of mental endowment. 

 Applying this test to the human prototype, we find that with respect 

 to his cerebral convolutions. Pithecanthropus stood considerably above 

 the other anthropoids, and within the line of development leading to 

 the higher human types. This is proved by the impressions on the 

 interior of the Java skull, which show that the superficies of the con- 

 volution of the prototype's brain was double that of the largest brain 

 of any anthropoid ape, and somewhat less than half that of the brain 

 of modem man. The convolutions themselves are also well marked 

 and distinctly human in form. Thus whether we judge from cranial 

 capacity or from cerebral convolutions, it is evident that the pliocene 

 precursor was psychically differentiated from the apes and endowed 

 with the intellectual attributes of man. 



Along physical lines the modification is even more marked. From 

 the shape of the femur (discovered in close proximity to the skull), it 

 is evident that Pithecanthropus stood erect and walked upright on the 



