24 THE KINGDOM OF MAN 



change. Assuming such a relative lull in the develop- 

 ment of mere mechanical form, it is obvious that the 

 opportunity for those individuals with the most * edu- 

 cable ' brains to defeat their competitors would arise. 

 No marked improvement in the instrument being possible, 

 the reward, the triumph, the survival would fall to those 

 who possessed most skill in the use of the instrument. 

 And in successive generations the bigger and more 

 educable brains would survive and mate, and thus 

 bigger and bigger brains be produced. 



It would not be difficult (though not, perhaps, profit- 

 able) to imagine the conditions which have favoured the 

 continuation of this process to a far greater length in 

 the Simian line of the pedigree than in other mamma- 

 lian groups. The result is that the creature called Man 

 emerged with an educable brain of some five or six 

 times the bulk (in proportion to his size and weight) 

 of that of any other surviving Simian. Great as is this 

 difference, it is one of the most curious facts in the 

 history of man's development that the bulk of his brain 

 does not appear to have continued to increase in any 

 very marked degree since early Palaeolithic times. The 

 cranial capacity of many savage races and of some of the 

 most ancient human skulls is only a little less than that 

 of the average man of highly-civilised race. The value 

 of the mental activities in which primitive man differs 

 from the highest apes may be measured in some degree 

 by the difference in the size of the man's and the ape's 

 brain ; but the difference in the size of the brain of 

 Isaac Newton and an Australian black-fellow is not in 

 the remotest degree proportionate to the difference in 

 their mental qualities. Man, it would seem, at a very 

 remote period attained the extraordinary development 

 of brain which marked him off from the rest of the 



