DR DUBOIS ON PITHECANTHROPUS ERECTUS. 87 



Orang-utan as observed by MM. Deniker and Boulart had a 

 weight of 400 grammes. 



From all these figures it is evident that even the largest cranial 

 capacities in anthropoid apes remain very much behind that 

 calculated for Pithecmithropus erectus. But on the other hand 

 the latter apparently approaches very near to some low normal 

 capacities in man. 



However, our fossil cranium may, by individual variety, acci- 

 dentally be a very large or a very small one of its kind. 



Individual variation in the size of the brain is, as we know from 

 observations on man, a very considerable factor. The individual 

 weight of the brain is however (as can be shown from the tables of 

 Boyd and from those of BischofT, if compared with the variation of 

 cranial capacity) very much dependent on the disease that was the 

 cause of death. The cranial capacity is therefore a much better 

 measure for judging of the individual variation in the size of the 

 encephalon. Now, in about 2000 observations of the capacity of 

 crania of all races and nations, taken from the records of many 

 authors, the greatest differences were nearly 20 per cent, superior 

 and 20 per cent, inferior to the average, and further it was apparent 

 that the probability is as 50 to 100 against i that the difference 

 of the capacity of a given human cranium, taken at random, is less 

 than \ of the average capacity, further that we may bet 8 to 16 

 against i that the difference is less than \ — \ from the average. 



Assuming thus our fossil cranium to be an individually very 

 large one, the average capacity in the species or the race might 

 have been 712 c. c, assuming it to be a very small individual 

 variety, the mean cranial capacity could have attained so much as 

 1070 c. c. 



Thus then considering the mere capacity, without taking into 

 account the size of the body, PitJiecanthropiis erectus certainly 

 approaches more to man than to the anthropoid apes. But on the 

 other hand the mere capacity is apparently not sufficient to separate 

 the fossil form from either the Hominida; or the Simiida^. The 

 largest capacity actually measured under many thousands on a 

 normal human skull, 2000 c.c. by the method of Broca, or 1890 c.c. 

 real volume, was that of a giant, and it would appear that some 

 equally high or even somewhat higher capacities or corresponding 

 brain-weights were due to pathological processes, such as internal 

 or external hydrocephalus. On the other hand, as far as could be 

 ascertained by me, all the available very low cranial capacities, 

 belonging to normal individuals, appear to have been accompanied 

 by small bodies. Australian women are certainly very slender and 

 light people, so are the Bushmen, the Weddas, the Andaman- 

 islanders and other negritos, which races afforded the lowest 

 cranial capacities, small-sized people. From the observations of 

 General Man the average height of the Andamanese men (48 

 individuals) is only 149 cm. and the body-weight (40 individuals) 



