Cell-Struggles in Same Organism 85 



struggle. The combats between cells resemble 

 the combats of two citizens within a well-organized 

 state, and the result is not total death but partial 

 death of the vanquished cells, i.e., simply a lessen- 

 ing of vitality. The organ in which the cells 

 secure a larger share of the blood supply increases 

 in size, while the organ or the tissue which is 

 vanquished is enfeebled; thus an athlete who 

 constantly uses his arms develops very large bi- 

 ceps, whereas a man who uses his brain intensively 

 employs most of his blood supply and energy to 

 feed the brain cells, while his biceps remain feeble. 

 Cells within an organism may be compared 

 legitimately to men in human society. They 

 are opposed to each other in a certain measure, 

 but in a more important way they are allied to each 

 other and depend upon each other. The signifi- 

 cant thing is that the cells do not attack each 

 other, and alliance in human society consists 

 exactly in this modification of the process of 

 struggle, the abandonment of attack against one's 

 neighbour. 



Another most instructive analogy between the 

 phenomena within an organism and the pheno- 

 mena of social life can be found in the researches 

 on cell life by Metchnikov and other naturalists. 

 These have shown that there are in the human 

 body errant cells which have two principal func- 

 tions : (i) that of combating the microbes of disease 

 which we take in by respiration and in other ways ; 

 and (2) that of doing, we might almost say, the 



