68 Hypothetical Bearers of Hereditary Characters 



equitable distribution of hereditary characters among the 

 two daughter-cells. It is not to be thought that to-day we 

 already stand at the end of our investigations concerning 

 the nucleus. On the contrary, the great discoveries 

 which have been made up to the present time awaken 

 within us the hope that many more complex processes 

 within the nucleus, and of which we have not, as yet, the 

 slightest inkling, will some time be discovered. The fact 

 that we do not know how the hypothetical pangens are held 

 together is in harmony with this statement. But this 

 question does not need to be solved by auxiliary hypothe- 

 ses. It is simply to be reserved for further study of the 

 phenomena within the protoplasts and their nuclei. 



An objection frequently urged is the necessity of as- 

 suming such a large number of different pangens. ^^ Ap- 

 parently the assumption of bearers of the whole specific 

 character is indeed much simpler. In that case only one 

 hypothetical luiit is required for each species. However, 

 if we do not limit ourselves to the consideration of one 

 species, but extend our view over the whole world of or- 

 ganisms, this objection breaks down, as has already been 

 said in the first Section ; for we then have to assume as 

 many units as there are and have been species, and their 

 number thus becomes increased without limits. But Dar- 

 win's units recur, most of them, in numerous plants or 

 animals, many in almost all of them, and a relatively 

 small number of such hypothetical pangens is sufficient 

 to explain, through the most varied possible groupings, 

 all the differences between species. On the whole, then, 

 the assumption of pangens is the simplest that can be 

 made, and this is obviously a great advantage. 



^^Cf. Weismann, Die Bedeutung der sexuellen Fortpflanziing. p. 

 102 seq. 1886. 



