CHAPTER XI 



THE DIVISION OF LYMPHOCYTES INDUCED BY THE ANILINE 



DYE THE AUGMENTING ACTION OF ATROPINE AND 



EXTRACT OF HAEMAL GLAND " AUXETICS " - THE 



CYCLE OF CELL-DIVISION THE POSSIBILITIES OF 



THE INDUCED CELL-DIVISION BEING DUE TO 

 " DEATH-STRUGGLES " ASYMMETRICAL AND RE- 

 DUCED DIVISIONS 



THE fact that mitotic figures could be made to appear 

 in lymphocytes was very satisfactory, for it seemed to 

 us to be a step in the solution of the problem of the 

 cause of the multiplication of cells. It was true that 

 we had only seen them in lymphocytes; but still these 

 mitotic divisions had occurred in response to the action 

 of a chemical substance, and if these cells were capable 

 of dividing in response to it, it appeared reasonable to 

 suppose that other cells would do the same and that 

 it was possible that they would only divide when they 

 absorbed a chemical substance. We believed at first, 

 of course, that the substance which had induced the 

 divisions was the extract of the dead haemal gland; 

 but before many experiments had been made this 

 suggestion received a check. One day a cell was seen 



225 



