320 THE ASCENT OF MAN 



\s so universal in all classes of multicellular organ- 

 isms, and nature deviates so rarely from it, that 

 it must necessarily be of pre-eminent importance. 

 If it be true that new species are produced by 

 processes of selection, it follows that the develop- 

 ment of the whole organic world depends on these 

 processes, and the part that amphigony has to play 

 in nature, by rendering selection possible among 

 multicellular organisms, is not only important, but 

 of the very highest imaginable importance." ^ 



These views may be each true ; and probably, in 

 a measure, are ; but the fact remains that the 

 later psychical implications of sex are of such 

 transcendent character as to throw all physical 

 considerations into the shade. When we turn to 

 these, their significance is as obvious as in the 

 other case it was obscure. This will appear if we 

 take even the most distinctively biological of these 

 theories — that of Weismann. Sex, to him, is the 

 great source of variation in Nature, in plainer 

 English, of the variety of organisms in the world. 

 Now this variety, though not the main object of 

 sex, is precisely what it was essential for Evolution 

 by some means to bring about. The first work of 

 Evolution always is, as we have seen, to create a 

 mass of similar things — atoms, cells, men — and the 

 * Biolof^cal Memoirs^ p. 281. 



