8o FOURTH GENERAL MEETING. 



These features perhaps may contribute to convince those who 

 still may doubt of the appertaining to the same individual of the 

 skull-cap and the femur. Further evidence, pointing to the same 

 conclusion, was afforded last year by the discovery of a new tooth. 



The Dutch-Indian Government, whose benevolent support has 

 enabled me to find and bring home a large collection of specimens, 

 mostly belonging to new species of fossil vertebrata, have still 

 further increased the debt which science owes to them on that 

 account. They ordered that the digging of a large irrigation canal, 

 cutting the ossiferous strata, should be surveyed by one of my late 

 assistants under my directions, and that at the same time the 

 excav'ations at Trinil should be continued during the dry season. 



Under the auspices of Mr Pierson, chief Civil Engineer and 

 director of those canal works, a valuable supplementary collection 

 has been made and was sent to me after my leaving Java. Thus 

 last year the above-mentioned tooth, which can only be attributed 

 to Pithecanthropus erectus, was found whilst removing a new part 

 of the ossiferous rock, lying close to the place where the skull-cap 

 and the two molars had been found, and exactly at the same level 

 of the strata. This tooth is one from the lozvcr jazv. It is the second 

 left premolar and bears in a more marked degree than the other 

 teeth an intermediate character. My well-founded hope, that in 

 the current year the inferior maxillary bone itself might be brought 

 to light, seems to have been sadly frustrated by certain unfavour- 

 able circumstances. 



Before speaking now of the conclusions to which I arrived 

 regarding the brain of PithecantJiropiLS erecttis, as founded upon 

 study of the cast of the interior of the skull-cap, I want to say a 

 few words about that skull-cap itself. 



The importance of this part of the skull is owing chiefly to its 

 having contained the most highly developed parts of the brain, 

 the cerebral hemispheres. Anatomists and anthropologists are 

 accustomed to draw some inferences as to the relative development 

 of these hemispheres of different races of men and also in comparing 

 man with the lower mammalia from the form of the skull-cap. I 

 have followed that practice during a certain time, but at last I 

 found that where we have to compare small species with large ones, 

 or such as occupy a very different degree in the scale of cerebral 

 development, we are liable to fall into grave errors. Indeed, the 

 cranium of a small animal possessing a quantity of brain relatively 

 very large, cannot directly be compared with that of a bulkier 

 species, the brain of which is relatively smaller. Therefore, for 

 instance, the greater relative height of the vault of the cranium in 

 the smaller species of Hylobates, when compared with the cor- 

 responding dimension in Hylobates syndactylus, appears to be a 

 simple result of the relatively larger maxillae of the latter. 



On the other hand, if an equally bulky species has an absolutely 

 much smaller brain, other organs (such as the eyes or the teeth), 



