The arguments founded upon the joint consideration of the length of the thigh-bone and the capacity of the skull are of the highest interest. For the former dimension provides a means of estimating approximately the body-weight, while the capacity gives an indication of the brain-weight. The body-weight is asserted to have been about 70 kgm. (eleven stone) and the brain-weight about 750 gm. And the ratio of the two weights is approximately 1⁄94. The corresponding ratios for a large anthropoid ape (Orang-utan) and for man are given in the table following, thus:
| Orang-utan | 1⁄183 |
| Pithecanthropus erectus | 1⁄94 |
| Man | 1⁄51 |
The intermediate position of the Javanese fossil is clearly revealed.
The same sequence is shewn by a series of tracings representative of the cranial arc in the middle line of the head (Fig. 1). And the results of many tests of this kind, applied not only by Professor Dubois but also by Professor Schwalbe, are confirmatory of the ‘intermediate’ position claimed for Pithecanthropus erectus. The molar teeth are of inadequate size if the skull-cap is that of an ape, whereas they are slightly larger than the corresponding teeth furnished by primitive existing human types. And now some of the objections to this account may be taken.
In the first place, the claim to Pliocene antiquity is contested. So keen an interest was excited by Professor Dubois' discovery that more than one expedition has been dispatched to survey and review the ground. It is now declared in certain quarters that the horizon is lower Quaternary: I do not know that any attempt has been made to reduce the age of the strata further. As the matter stands, the difference is not very material, but Professor Dubois refuses to accept the revised estimate and still adheres to his own determination. Incidentally the more recent work (Blanckenhorn[2], 1910) has resulted in the discovery of a tooth claimed as definitely human (this is not the case with the teeth of Pithecanthropus erectus), and yet of an antiquity surpassing that of the remains found by Professor Dubois. The latter appears unconvinced as to the genuineness of the find, but no doubt the case will be fully discussed in publications now in the course of preparation.
Fig. 1. Outline tracings of skulls reduced in size to a common dimension, viz. the line Gl—Op, representing a base-line of the brain-case. Pe, Pithecanthropus. Papua, a New Guinea native. Hl, Sm, At are from skulls of monkeys. (After Dubois.)