48o THE WONDER OF LIFE 



that the tendency to complexify that is seen in things 

 inanimate is carried on into organisms, and finds expression 

 in variation. 



There are many peculiarities in the bodies of higher 

 animals which are certainly not the direct results of some 

 peculiarity in the environment, but are, we believe, the 

 expression of variations in the germinal substance. Yet it 

 has to be remembered in regard to these variations that the 

 environmental pecuharities may have served to prompt 

 the germ-cells to some internal re-arrangement of their 

 organization. 



Weismann has laid emphasis on the fact that the ger- 

 minal substance in the germ- cells is subjected to the changes 

 and fluctuations in the nutritive stream, and it is possible 

 that these may serve to prompt germinal variations. He 

 has also suggested that there may be within the germ-cell 

 a hteral struggle among the hereditary items or factors, 

 just as there is a struggle among the different parts of the 

 body. 



Another consideration is this, that in the ripening of the 

 egg-cell there appears to be an opportunity for the dropping 

 out of hereditary items, and as a matter of fact we know 

 that items are very often dropped out. In albinos a pig- 

 ment-producing or pigment-completing factor is dropped 

 out. Moreover, in fertilization, as we have seen, there are 

 opportunities for new permutations and combinations, 

 when the paternal and maternal contributions enter into 

 intimate and orderly union. Two sex-ceUs become one — 

 a unified individual, not merely an inheritance-packed cell. 

 In the compromise efiected between similar items, in the 

 unified organization arrived at, there is probably many an 

 opportunity for something new. 



