36 THE BIOLOGICAL PROBLEM OF TO-DA Y 



have to deal with what is merely a fallacy in 

 rhetorical disguise. For, from the premiss that 

 the chromatin has the power of impressing specific 

 character upon the protoplasm of the cell, it by no 

 means follows that two cells, distinguishable by the 

 nature of their plasma-products, must therefore 

 contain different kinds of protoplasm. There are 

 other possibilities to be reckoned with. Weismann 

 himself knows that there is no logical necessity for 

 the conclusion, for he himself suggests another 

 possibility in the following : ' If we wished to 

 assume that the whole of the determinants of the 

 germplasm are supplied to all the cells of the 

 entogeny, we should have to suppose that differ- 

 entiation of the body is due to all the determinants 

 except one particular one remaining dormant in a 

 regular order, and that, apart from special adapta- 

 tions, only one determinant reaches the cell, viz., 

 that which has to control it. If, however, we do 

 make the assumption,' etc. (p. 63, English edition). 



Here, then, Weismann himself points out that 

 what in other places he has attempted to represent 

 as a necessary conclusion is but one of two alter- 

 natives. 



Not only does he grant the possibility of the 

 alternative, but uses it himself in explanation of the 

 phenomena of reproduction and development. He 

 attributes to certain series of cells, in addition to 

 the active rudiments controlling the normal cha- 

 racters of their protoplasm, the possession of 

 numerous latent rudiments which become active 

 when opportunity presents itself. 



