508 STUDIES IN GENERAL PHYSIOLOGY 



liquefaction of the pseudopodia upon the removal of the 

 nucleus, and the inability of Infusorian fragments with- 

 out a nucleus to form a new cuticle, correspond entirely 

 with the assumption that the cell fragments without a 

 nucleus are in a condition of decreased oxidative activity. 



I have expressed this view for several years in my lec- 

 tures, and I have had it in mind to perform experiments 

 on pieces of Infusoria without the nucleus under increased 

 oxygen pressure. If my theory be correct, it should be 

 possible to prolong the life of fragments of protoplasm 

 freed from the nucleus by furnishing them a better supply 

 of oxygen. But it seems to me that this experiment has 

 already been made. For while Nussbaum, Gruber, and 

 Verworn found that pieces of Infusoria without the nucleus 

 go to pieces after two days, and only exceptionally live 

 several days, all botanists who have made the same ex- 

 periment on chlorophyll-bearing-cells (for example, Algae) 

 have found that cell fragments without the nucleus remain 

 alive five to six weeks. 1 Assimilation took place in such 

 pieces. It seems to me that the comparatively long dura- 

 tion of life of fragments of Algse without a nucleus is of 

 great importance in judging of the function of the cell 

 nucleus. As is well known, oxygen is liberated in the 

 assimilation of carbon dioxide. Pieces of Algse without a 

 nucleus are therefore, in the light, under better conditions 

 of oxygen supply than fragments of Infusoria without a 

 nucleus, for the Infusorian contains no chlorophyll. 



It seems to me, therefore, that all the facts which are known 

 thus far very naturally support the idea that the nucleus 

 is the organ of oxidation of living matter; and that frag- 

 ments of cells without a nucleus are not able to regenerate 

 because their oxidative activity has fallen to too low a 

 point. Such pieces die slowly from asphyxia. 



i KLEBS, Biologisches Centralblatt, Vol. VII (1888). 



