56 An Examination of Weismannism. 



genesis supposes them to originate at the periphery, 

 and then to travel centripetally. 



This point of difference, however, arises from the 

 deeper ones, which — having now exhausted the points 

 of agreement — we must next proceed to state. 



If, as we have seen. iC formative material" and 

 "germ-plasm " agree in being particulate ; in consti- 

 tuting the material basis of heredity ; in being mainly 

 lodged in highly specialized, or germinal, cells ; in 

 being nevertheless also distributed throughout the 

 general cellular tissues, where they are alike concerned 

 in all processes of regeneration, repair, and a-sexual 

 reproduction ; in having an enormously complex 

 structure, so that every constituent part of the future 

 organism is already represented in them by corre- 

 sponding particles ; in being everywhere capable of a 

 virtually unlimited multiplication, without ever losing 

 their hereditary endowments ; in often carrying these 

 endowments in a dormant state through a number of 

 generations, until at last they re-appear again in what 

 we recognize as reversions to ancestral characters ; — 

 if in all these most important respects the two sub- 

 stances are supposed to be alike, it may well appear 

 at first sight that there is not much room left for 

 any difference between them. And. in point of fact, 

 the only difference that does obtain between them 

 admits of being stated in two words, — Continuity, 

 and Stability. Nevertheless, although thus so few in 

 number, these two points of difference are points of 

 great importance, as I will now proceed briefly to 

 show. 



If the substance which constitutes the material 

 basis of heredity has been perpetually continuous, in 



