78 THE BIOLOGICAL PROBLEM OF TO-DAY 



of an organism possess, in addition to their patent 

 microscopical characters, latent characters, which 

 show themselves to be peculiar to the species. 



How does Weismann attempt to reconcile his 

 hypothesis of differentiating division with these 

 facts ? By the provision of different complementary 

 hypotheses, which, as we have seen, amount to 

 this, that he allows the set of rudiments which he 

 had turned out by differentiating division of the 

 cell to creep in again by a back-door. He accom- 

 plishes this by his idea that the germplasm may un- 

 dergo, simultaneously, doubling and differentiating 

 division. In these cases cell-division has a double 

 aspect. According to Weismann, this is possible, 

 because the egg contains many, sometimes as many 

 as a hundred, ids, each of which is a combination 

 representing the species. Weismann believes that 

 in an egg, while it is preparing for its first division, 

 the ids are arranged in two groups an active army 

 and a reserve army. By differentiating division 

 the active army is broken up into the divisions, 

 brigades, and regiments of determinants appropriate 

 to the separate groups of cells, and so the course 

 of the development is conducted according to a 

 preconceived plan. On the other hand, the passive, 

 reserve army multiplies by doubling division, and 

 is sent along with definite parts of the active army 

 as baggage in a fixed or inactive condition, so that 

 it has no influence upon the normal course of 

 development nor upon the characters of the cells 

 (fixed germplasm, inactive, accessory idioplasm, 

 bud-idioplasm). 



