CHAP. Ill The Struggle of Life 39 



lupus, also. . . . The struggle is fierce between allied kinds, and 

 fiercest of all between individual members of the same species." 



I have quoted these sentences because they are clearly and 

 cleverly expressed, after the manner of Grant Allen, but I 

 do not believe that they are true statements of facts. The 

 evidence is very unsatisfactory. In his paragraph sum- 

 marised as "struggle for life most severe between indi- 

 viduals and varieties of the same species ; often severe 

 between species of the same genus," Darwin gave five 

 illustrations : one species of swallow is said to have ousted 

 another in North America, the missel-thrush has increased 

 in Scotland at the expense of the song-thrush, the brown 

 rat displaces the black rat, the small Asiatic cockroach 

 drives its great congener before it, the hive-bee imported 

 to Australia is rapidly exterminating the small, stingless 

 native bee. But the cogency of these instances may be 

 disputed : thus what is said about the thrushes is denied by 

 Professor Newton. And on the other hand, we know that 

 reindeer, beavers, lemming, buffaloes and many other 

 animals migrate when the means of subsistence are unequal 

 to the demands of the population, and there are other 

 peaceful devices by which animals have discovered a way 

 out of a situation in which a life-and-death struggle might 

 seem inevitable. Very instructive is the fact that beavers, 

 when too numerous in one locality, divide into two parties 

 and migrate up and down stream. The old proverb which 

 Grant Allen quotes, Homo homini lupus, appears to me a 

 libellous inaccuracy ; the extension of the libel to the 

 animal world has certainly not been justified by careful 

 induction. For a discussion of the alleged competition 

 between fellows, I refer, and that with pleasure and grati- 

 tude, to Kropotkine's articles on " Mutual Aid among 

 Animals," Nineteenth Century, September and November 

 1890. 



(b) Of the struggle between foes differing widely in kind 

 little need be said. It is very apparent, especially in wild 

 countries. Carnivores prey upon herbivores, which some- 

 times unite in successful resistance. Birds of prey devour 



