The Influence of the Nucleus in the Cell 183 



brids produced by two species, in which the one species 

 will function at one time as the father and at another 

 time as the mother, with few exceptions, essentially alike. 

 There is no ground for the assumption that the hereditary 

 characters, latent in the egg-cell and in the spermatozoid, 

 are inherited in a fundamentally different manner from 

 the father than from the mother. And thus we arrive at 

 the conclusion that the latter, too, must lie in the nu- 

 cleus, and are not distributed over the individual organs 

 of the egg-cell. 



Hence the nuclei are the bearers of the latent hered- 

 itary characters. In order to become active, the greater 

 part of these characters,-^ at least, must pass from the 

 nuclei into the other organs of the protoplasts 



6. Observations on the Influence of the Nucleus in the 



Cell 



Even the first investigators of this organ realized 

 that the nucleus plays a prominent role in the life of the 

 cell. They have given expression to this conviction in the 

 name itself. And, although later the supposed absence of 

 the nucleus in large groups among the Thallophytes gave 

 rise to a doubt as to the correctness of this opinion,"^ it 

 has been entirely removed by more recent investigations. 



At first it was impossible to form any idea as to the 

 nature of that role. The investigators mentioned in the 

 first chapter of this Section, Haeckel, Hertwig, Flem- 

 ming, Strasburger, and others, were the first to teach us 

 to regard the nucleus as the real organ of heredity. 

 And even in these later years there are some authors who 



28The characters that regulate nuclear division, are probably 

 active in the nuclei themselves. 



29Cf. Briicke, Sitzungsher. Akad. Wiss. Wien. 1861. 



