NATURAL HISTORY STUDIES 



Among living creatures we see three different 

 forms of the struggle : between fellows, between 

 foes, and with fate. When the locusts of a huge 

 swarm have eaten up every green thing, they some- 

 times turn on one another. This cannibalism among 

 fellows of the same kith and kin is seen also among 

 many fishes ; it is the most intense and also the 

 ugliest form of the struggle for existence. An eerie 

 example of it cannibalism in the cradle occurs 

 among the young of the great whelk or roaring 

 buckie within their egg -cases, which are often 

 thrown up in great bunches on the seashore, and 

 also in the vase-like egg-cases of the common dog 

 whelk, which are fastened to the rocks. The same 

 sort of struggle is seen between thick-sown seedlings 

 of the same kind, which compete with one another 

 for room and food and light. In his Woodman, 

 Robert Louis Stevenson speaks of the warfare in 

 the dense tropical forest where the silent foes 

 " grapple and smother, strain and clasp," but neither 

 among plants nor among animals need the struggle 

 be direct the whole point is that the competitors 

 seek after the same things of which there is but 

 a limited supply. Whether a full-grown frog eats 

 a tadpole of its own kind, or coral polyps compete 

 silently for the same niche among the rocks, or 

 the rabbits for the scarce grass on the dunes, the 

 general fact is the same in all cases, and, apart from 

 chance, the result will be the same : the survival of 

 those fittest for the particular conditions of life. 

 The struggle may be for food, or foothold, or breath- 

 ing-space, or what is sought after may be some 



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