The Survival of the Non- Nucleated Cell. 



All observations made upon cells which have been 

 deprived of their nuclei prove conclusively that non- 

 nucleated protoplasm is destined to ^pow- without growing 

 or dividing. But in most cases, particularly in ameba, it 

 has been impossible to get this protoplasm to take in food, 

 and even that food which is already included in the proto- 

 plasm is but imperfectly digested. Consequently it is fair 

 er to compare the survival of an enucleated cell with one 

 which has been isolated without food, rather than with an 

 actively feeding cell. When this is done, it is found 

 that the non-nucleated oell lives almost as long as the 

 nucleated one, provided there is no d ifference in size. 

 If an ameba is cut into unequal parts, the nucleus, owing 

 to its central position, will usually be found in the 

 larger part. Since large fragments live longer than small 

 ones, special car^e must be taken to avoid a difference in 

 size. 



Fifteen amebas were cut in half, and both halves 

 were kept without food in either distilled water or in 

 water taken from the culture. The number of days which 

 each piece lived after the operation is given in the 

 following table: 



(29) 



