PROLIFERATION OF HEALING 31 



molecules common to all the kinetics which 

 could be held responsible for their action, either 

 as excitors of amoeboid movements or as aug- 

 mentors. They seem to belong to certain groups 

 (e.g. alkaloids, primary aromatic amines), but the 

 constitution of their molecules differs widely. 



Hence we cannot form any definite opinion as 

 to how the auxetic immediately causes cell- 

 division, or the kinetic excitation or augmen- 

 tation. It is evidently some chemical process 

 which goes on between the substances concerned 

 and the living cell protoplasm. We think that 

 until more is known about the constitution of the 

 latter it is useless to suggest any theory. 



With regard to the action of the aniline dyes, 

 however, it may be pointed out that these dyes 

 cause gradual (presumably molecular) death of 

 the cells, because the granules can be seen to 

 stain one by one while the cell is alive ; but 

 so soon as the nucleolus is reached by the stain, 

 cell death occurs. The natural auxetics contain- 

 ing the amidine grouping are set free by the 

 death of protoplasm, and it is possible that the 

 aniline dyes, by causing gradual molecular death 

 of part of the cell protoplasm, may be the in- 

 direct means of setting free the auxetics from 

 that protoplasm, which in their turn induce the 

 cell to divide. This is a speculation which we 

 think one is justified in suggesting, because there 

 appears to be no experimental method by which 

 it can possibly be elucidated. 



Lymphocytes are induced to divide, then, by 

 substances containing the amidine grouping, 

 which are set free in any part of the body where 



