This accords with the estimate of the brain capacity[P] of 855 c.cm. (Dubois) as compared with 1,230 c.cm., the smallest brain capacity found in a member of the Neanderthal race. Second, as seen from above, we are struck with the great length of the calvarium as compared with its breadth, the cephalic index or ratio of breadth to length being 73.4 per cent (Schwalbe) as compared with 73.9 per cent in the Neanderthal type skull; this dolichocephaly accords with the fact that all of the earliest human races thus far found are long-headed, although according to Schwalbe(22) all anthropoids are broad-headed. This is a very important distinction. The third feature is the prominence and width of the bony eyebrow ridges above the orbits, which are almost as great as in the chimpanzee and greatly exceed those of the Neanderthal race and of the modern Australian. The profile of the Trinil head restored by McGregor (Fig. 38) exhibits this prominent bony ridge and the low, retreating forehead. In the latest opinion of Schwalbe(23) _Pithecanthropus_ may be regarded as one of the direct ancestors of Neanderthal man and even of the highest human species, _Homo sapiens_. He also considers that when the lower jaw of the Trinil race becomes known, it will be found to be very similar to that of the Heidelberg man, the final conclusion being that _Pithecanthropus_ and the nearly allied Heidelberg man may be regarded as the common ancestors of the Neanderthal race, on the one hand, and of the higher races on the other. There are, however, reasons for excluding _Pithecanthropus_ from the direct ancestral line of the higher races of man. [Illustration: FIG. 36. Profile of the skull of _Pithecanthropus_, as restored by J. H. McGregor. 1914. One-third life size.] This prehuman stage has, none the less, a very great significance in the developmental history of man. In our opinion it is the very stage which, theoretically, we should anticipate finding in the dawn of the Pleistocene. A similar view is taken by Büchner,(24) who presents in an admirable diagram (Fig. 117) the result of his comparison of twelve different characters in the skulls of _Pithecanthropus_, the Neanderthals, the Australians, and the Tasmanians. One of the main objects of Büchner's research was a very detailed comparison of the Trinil skull with that of the lowly and now extinct Tasmanian race, which, we observe in the diagram, occupies a position only a little higher than that of the Spy-Neanderthal race. [Illustration: FIG. 37. Three views of the skull of _Pithecanthropus_, as restored by J. H. McGregor, showing the original (shaded) and restored (black lines) portions. About one-quarter life size.]