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." 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, Pfliigers Archiv, Vol. LXIX (1897). 



