Active and Inactive Pang ens 199 



every time in order, by further multiplication, to impress 

 the characters of which they are the bearers, on a given 

 part of the cytoplasm. This process would repeat itself 

 at every change of function of a protoplast; every time 

 new pangens would leave the nucleus in order to become 

 active. In this way the whole cytoplasm would soon 

 consist of pangens drawn from the nucleus, and of their 

 descendants. 



j. Active and Inactive Pangens 



Darwin has already emphasized the fact that the 

 transmission of a character and its development, even 

 though they frequently occur conjointly, are yet distinct 

 powers. 2 This point, derived from the phenomena of 

 atavism, has attained great significance in cell-theory 

 through the discovery of the function of the cell-nucleus. 

 i The function of the nucleus is transmission, that of the 

 cytoplasm, development. 



Former theories assumed a complete contrast be- 

 tween nucleus and cytoplasm, imagining hereditary char- 

 acters to be limited to the former, and seeing in the rest 

 of the protoplasm only a passive substratum, by means 

 of which the nuclei do their work. Thus the nucleus 

 became the essential part of the cell ; not only did it dom- 

 inate, but also completely determine the functions. But 

 the experiments of Nussbaum, Gruber, Klebs, and others 

 have taught that non-nucleated fractional parts of lower 

 organisms are also able to exercise certain functions. 

 Especially do they seem to possess the power of contin- 

 uing later those functions in which they were already 

 engaged before being detached. Hence, the influence 



2 Darwin, The Variation of Animals and Plants. 2: 381. New 

 York. 1900. 



