32 



THE HISTORY OF ECOLOGY 



war of each against all was the normal state 

 of existence,' he was, not for the first time, 

 overstating the case." 



In the Descent of Man Darwin gave nat- 

 uralistic examples of mutual aid. His whole 

 thesis that man is descended from other 

 animals requires that he should recognize 

 that man's altruistic drives should have 

 their precursors among his nearer ancestors 

 and would probably be recognizable among 

 his closer living relatives. 



That the individualistic emphasis was 

 common in British scientific circles during 

 Darwin's later life and that group-centered 

 interpretations were novel is shown by the 

 following quotation from Nature (21: 285, 

 Jan. 22, 1880) : 



"We notice an important communication 

 which was made by Prof. Kessler at the annual 

 meeting of the St. Petersburg Society of 

 Naturalists on January 8, [1880] on the 'Law 

 of Mutual Help,' as one of the chief agents in 

 the development and progress of organisms. 

 Prof. Kessler, although an able follower of 

 Darwinism, thinks that the struggle for exist- 

 ence would be insufficient to explain the 

 progress in organic life, if another law, that of 

 sociability and of mutual help did not power- 

 fully work for the improvement of the organ- 

 isms and for strengthening the species . . . ." 



Espinas' (1877) great work, which pre- 

 ceded Kessler's lecture, emphasizes the 

 naturalness of the cooperative social drives; 

 Darwin-like, he implemented his conclu- 

 sions by pertinent observations drawn from 

 many aspects of natural history and from 

 various levels of the animal kingdom. He 

 had little immediate influence upon the 

 thinking of the biologists, although more 

 recently many have come to recognize the 

 value of his work. Thus Deegener (1918) 

 and Wheeler (1923 and later) give evi- 

 dence of having been influenced by his 

 ideas and by the evidence he collected. 



Forbes (1887) recognized the existence 

 of cooperative interests even in apparently 

 opposed forces in the ecological community. 

 He said: 



"It is a self-evident proposition that a species 

 cannot maintain itself continuously, year after 

 year, unless its birth-rate at least equals its 

 death-rate. If it is preyed upon by another 

 species, it must produce regularly an excess of 

 individuals for destruction, or else it must cer- 

 tainly dwindle and disappear. On the other 



hand, the dependent species evidently must 

 not appropriate, on an average, any more than 

 the surplus and excess of individuals upon 

 which it preys, for if it does so, it will continu- 

 ously diminish its own food supply, and thus 

 indirectly, but surely, exterminate itself. The 

 interests of both parties will therefore be best 

 served by an adjustment of their respective 

 rates of multiplication, such that the species 

 devoured shall furnish an excess of numbers 

 to supply the wants of the devourer, and that 

 the latter shall confine its appropriations to the 

 excess thus furnished. We thus see there is 

 really a close community of interest [sic] be- 

 tween these two seemingly deadly foes." 



Kropotkin's writings (1902) on mutual 

 aid are still quoted, perhaps more fre- 

 quently by less critical students, and, to- 

 gether with the teachings of Geddes and 

 Thompson, serve to round out the develop- 

 ments in this aspect of ecology at the turn 

 of the century. Needless to say, the new 

 century opened with the emphasis still 

 centered upon the individual and his prob- 

 lems rather than upon the group, whether 

 as a community, a more closely knit bio- 

 coenosis, a population, or a mere aggrega- 

 tion of organisms. 



Despite the development of the coopera- 

 tive idea by Delage and Goldsmith (1912), 

 Reinheimer (1913), and Patten (1916), the 

 turn toward present day emphasis on the 

 importance of natural cooperation did not 

 come until about the beginning of the 

 1920's; this development will be traced in 

 the following chapter. 



During the second half of the nineteenth 

 century considerable attention was given to 

 the phenomenon of symbiosis, more, it 

 seems, as an oddity in an egocentric world 

 than as an indication of any general under- 

 lying biological principle. The writings of 

 Van Beneden and of Oskar Hertwig illus- 

 trate the point. Later, in the first decades of 

 the present century, Kammerer and 

 Deegener, among others, saw the more 

 general implications of widespread sym- 

 biosis. 



THE NATURALISTS 



Ecologists have not usually been greatly 

 concerned with biological theory. Converse- 

 ly, they have kept their feet planted, as 

 firmly as the often slippery substratum 

 would permit, on the soil or in the mud 

 and water of field experience. This tend- 



