CHAPTER XXVIl 



THE COMPETITIVE SYSTEM AMONGST THE LOWER 



ANIMALS AND WITH MAN* 



"Struggle for existence" and "survival of the fittest" have 

 been regarded as universal biological laws during the past 

 half century. "Cooperative or social survival and evolution" 

 have been practically entirely overlooked.* In the present 

 chapter an effort is made to condense and recapitulate facts 

 regarding the former. In the succeeding chapter the law of 

 cooperative evolution will be examined. Thereafter a com- 

 parison will be made between the two. 



It is generally conceded that the most fundamental factor 

 in determining the abundance, distribution, and continued 

 existence of animal life is the food supply, included under 

 which is water. All others are secondary in importance. If 

 we neglect the simpler groups, it may be said that from the 

 arthropods upward all animals can be classified in rather gen- 

 eral terms under four categories as follows: 



(a) Carnivorous, predatory, and competitive types. 



(b) Carnivorous, semi-predatory, and semi-social types. 



(c) Largely phytivorous, feebly predatory, and social types. 



(d) Phytivorous, peaceful, and social types. 



The first group includes examples that live wholly alone 

 except during the breeding season, and when the young are 

 being reared; or that consort only in sex-pairs throughout 

 life. Illustrations are seen in the solitary crabs and lobsters, 

 the arachnids generally, many myriapods and insects, a con- 

 siderable number of the molluscs, many fishes, about one-half 



* The writer was not aware, when he wrote the above, of the existence of 

 Krapotkin's remarkable work, "Mutual Aid, a Factor in Organic Evolution." 

 In next chapter it is commented on, but should be read by all as one of the 

 most valuable contributions ever made to Biological Science, and presented 

 in that lucid and attractive stvle which is so characteristic of the author's 

 writings. 



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