298 THE ISSUES OF LIFE 



ping them so that they have a rather shorter life or a rather 

 less numerous or less successful family. This is precisely 

 what eugenists of the gentler persuasion wish to see in opera- 

 tion in mankind the replacement rather than the destruc- 

 tion of the baser sort. 



As is well known, the struggle for existence takes three 

 main forms: (a) between fellow-organisms of the same 

 kith and kin, (6) between foes of entirely different kinds, 

 and (c) between living creatures and the physical fates. 



In regard to the first, Darwin headed a paragraph " Strug- 

 gle for Life Most Severe Between Individuals and Varieties 

 of the Same Species ", and that paragraph, along with a 

 subconscious desire to get a theoretical backing for individu- 

 alistic human practices, has given rise to the widespread idea 

 that what is most characteristic of Nature is an internecine 

 competition of near kin for food and foothold. 



But it is very profitable to examine Darwin's evidence 

 for his momentous conclusion. Not that we doubt that keen 

 competition between fellows is one mode of the struggle for 

 existence; the point is to what extent it obtains. The gladia- 

 torial show conception of Animate Nature is illustrated by 

 the supposed internecine competition between brown rat and 

 black rat, and might almost be called the rat theory of life. 

 The story of this internecine competition, for which Darwin 

 is largely responsible, is well known, but it suffers from 

 the demerit of not being quite true. Long ago Britain had 

 only the Black Rat (Mus rattus) which probably came from 

 Asia through Mediterranean ports. It seems to have been 

 introduced into Western Europe by the ships of the 

 Crusaders. The Brown Rat (Mus decumanus), also of East- 

 ern origin, was a later arrival, becoming common in the early 

 part of the eighteenth century. 



