REGENERATION OF PROTOPLASMIC FRAGMENTS 509 



The question as to the significance of the nucleus for 

 development and heredity enters into a new light if these 

 ideas are correct. Nor can it longer be held that the living 

 organism is merely a combination of individual cells. "By 

 cellular structure we understand the fact that there must be 

 a definite maximal distance, variable, however, for different 

 forms and tissues, between the elements of the protoplasm 

 and the nearest nucleus." 1 We can now understand the 

 reason for this. If the distance becomes too great, the 

 particular protoplasmic element goes to pieces from as- 

 phyxia. That besides this an interchange of other sub- 

 stances occurs between the protoplasm and the nucleus I 

 will, of course, not deny ; it is possible or probable that the 

 significance of the cell nucleus is not exhausted by its oxida- 

 tive activity. It is also scarcely necessary to point out par- 

 ticularly that I do not believe that without the nucleus all 

 processes of oxidation cease in the protoplasm; it rather 

 seems from all the facts at hand that it is only markedly 

 decreased. 



i LOEB, Pflilgers Archiv, Vol. LXIX (1897). 



