96 ESSAYS OF A BIOLOGIST 



Nations, has already generated the seeds of what 

 will in time devour it.^ 



To sum up, we may say that the crude application 

 to human affairs of the doctrine of the struggle for 

 existence, torn from its biological context, isolated 

 and over-emphasized, is wholly unwarranted. On 

 the other hand, a struggle does continue, both of the 

 direct and indirect type defined by Darwin: and 

 there is no prospect of it ceasing to play an important 

 part in human biology. Co-operation is not, any 

 more than competition, to be taken as the sole desir- 

 able principle. Panaceas of this sort do not exist, 

 except to make bubble reputations and quack for- 

 tunes. Even within such a highly organized co- 

 operative unit as the mammalian body a struggle 

 continues — the different tissues are in competition 

 with each other for food, and if the available supply 

 diminishes below the necessary level, some tissues 

 will be drawn upon by other more successful com- 

 petitors, and the struggle will lead to an end-result 

 in which the proportion of the various kinds of cells 

 comes to be very different from what they were in 

 the normal well-nourished body."^ That is a purely 

 biological example. In man, since the unification of 

 the community is of a low order, it is inevitable that 

 individuals and sections will continue in some form 

 of competition with each other: not only this, how- 



«See, e.g., Wells, '21, pp. 558, 666. 



T See Roux, '81, for a discussion of this important extension of 

 Darwinism. 



