VARIATION 429 



in the division of the germ-cells before fertilisation, where 

 there has to be a partition of a complex cytoplasmic and 

 chromosomic cargo between two vessels, losses and augmenta- 

 tions and inequalities may be expected in the transhipment. 



(3) That in fertilisation, with its intimate and orderly 

 union of paternal and maternal contributions (amphimixis), 

 there may be opportunity for new permutations and combina- 

 tions, the result normally being a viable unity of dual origin. 



(4) That there may be growth-changes, or regulative re- 

 organisation processes, or rejuvenescences in the germ-cells in 

 the course of their history ; and it is possible that there may 

 be something in Weismann's hypothesis of intra-germinal 

 struggle. 



We are thus aware of certain originative factors in evolu- 

 tion, which admit of experimental testing, and we should 

 not lose sight of any of them. Each must be pushed as far 

 as it will go. Recognising this, some will insist that there 

 is no more to be said, but much to be done. We venture 

 to doubt, however, whether this is not making a tyranny 

 of scientific method (which, after all, is very selective and 

 partial) and giving up the right of speculative adventure. 

 As Karl Ernst von Baer, the great Russian embryologist, 

 said: There is observation, but there is also reflection. 



Those who have devoted much attention to the occurrence 

 of variation, we think for instance of Darwin and Bateson, 

 have given emphatic expression to their sense of the difficulty 

 of accounting for the origin of the new. The fountain of 

 change, whence are its well-springs ? " As to almost all the 

 essential features, whether of cause or mode, by which specific 

 diversity has become what we perceive it to be, we have to 

 confess an ignorance almost total " (Bateson, 1913, p. 248). 

 But we also notice that some of those who have given much 



