264 



care, in order lo observe in detail what happened; and it 

 was very easy indeed lo see, that the two eells divided 

 and Ihal all llic I lU'w cells moved away in differeiU direc- 

 tions with a lively prol()i)lasnde inov'emenl. In one ol' the 

 observations, it was possible to I'ix and stain the culture 

 immediately alter the interesting cell division and later 

 find the cells again, thereby controlling the observation 

 of the living cells with the same cells in fixed and stained 

 condition. This conjugation, if we may so term it. followed 

 by the cell division, can be seen in fig. 66. 



Fig.768. 



Tfie type of spindle-stiaped cells of ttie Rous's sarcome, 



stained with methylene blue. 



It was frequently observed, that the isolated sarcoma 

 cells divided independently. The new cells were very often 

 much smaller than the mother cells. Any mitosis has not been 

 observed. In an extreme case, one single cell separated 

 cells which were many times smaller than the mother 

 cell, and it was observed how one cell finally was split 

 up into seven small cells. It is noteworthy that all the 

 small were moving alx)ut. No wonder that the picture of 

 the sarcomatous tissue is very polymorphous, when the 

 cells are able to divide, separating cells of different sizes. 



In some preparations a kind of struggle between two cells, 

 not belonging to the same type, was observed. Fig. 70 



