328 AUGUST WEISMANN [april 1899 



field of Nature and Life, that it has been modified according to new 

 discoveries, which it has itself in part brought about. That it should 

 be capable of such modification without giving up its fundamental 

 principles seems to me an advantage, and I trust that in the future, 

 even more than in the past, the theory of the germ-plasm will do good 

 service in widening our knowledge of heredity. 



zoologisches i> t stitut, 

 Freiburg-i.-Br. 



