338 THE CHEMISTRY OF PROLIFERATION 



the number of births. If an individual cell dies, its 

 death causes its neighbours to multiply to supply the 

 deficiency; but if the cell-death is extensive owing to 

 damage, the proliferation of those cells which have not 

 been killed will also be extensive, and this proliferation 

 will now be extended to that of the white blood-cor- 

 puscles which have been shed during and after the 

 injury; and the result will be the cell-proliferation of 

 healing. 



Judging from the experiments which have been 

 made, it may also be assumed that since the number 

 of cell-births depends upon the number of cell-deaths, 

 and since an increase in the number of births must 

 increase the number of deaths, it follows that the 

 number of deaths must also depend to some extent 

 on the number of births. Presumably, if once cell- 

 division is set going in a tissue or in a part of a tissue, 

 that cell-division will go on increasing until something 

 restrains it. Elimination from a tissue of tissue fluids 

 would restrain it; for if the soluble remains of dead 

 tissues become quickly eliminated, the diffusion of the 

 constituents of these fluids into the cells would also be 

 arrested, for that diffusion varies directly with the 

 factor time. In a damaged tissue the vessels and 

 lymphatics are also damaged, and elimination may be 

 impaired ; hence the remarkable cell-proliferation which 

 leads to "granulation tissue." In an injury of any part 

 except the cornea, coagulation of the shed blood occurs ; 

 the red cells become laked, and ultimately the haemo- 

 globin is evidently decomposed, as evinced by the 

 pigmentation which will always be seen even in a 



