52 



THE HISTORY OF ECOLOGY 



proach to ecology and presented something 

 of the impact of human society on a nat- 

 ural environment. Their interest centered 

 around the Illinois River as it had been af- 

 fected by (a) the opening of the Chicago 

 drainage canal into the river; (b) the con- 

 sequent increase in sewage; (c) the recla- 

 mation of river bottoms for agricultural use; 

 and (d) the introduction into the stream 

 of the European carp. 



An appreciation of the amount of pub- 

 lished research on limnology through the 

 first decade can be had by examination of 

 the "Bibliography of Limnological Litera- 

 ture" compiled in the "Challenger" ofiice 

 and assembled by James Chumley (1910). 

 The reference list contains over 2500 cita- 

 tions. 



In discussing some of the developments 

 of synecology during this decade, it is well 

 to remind the reader that many of the 

 papers already cited in other connections 

 contain much of synecological interest. 

 Thus, the reports of Pearse and Achtenberg, 

 of Petersen and Jensen, of Embody and of 

 Muttkowski all have direct bearing and 

 could be cited properly in this section. 

 However, we shall extend our remarks 

 somewhat by reviewing a few more papers 

 selected for the purpose. 



During this decade synecological studies 

 were varied in character and in method of 

 analysis. They were dominated largely by 

 successional emphasis and ranged from such 

 papers as that of Gates (1911), describing 

 the distribution of summer Illinois bird life 

 in relation to the local plant communities, 

 to Wheeler's (1911) philosophical essay, 

 "The Ant-Colony as an Organism," in 

 which he pointed out some of the analogies 

 between such a complex, integrated popula- 

 tion of organisms and a complex, integrated 

 population of cells. 



In 1912 Pierce, Cushman, and Hood pub- 

 lished an important paper on "The Insect 

 Enemies of the Cotton Boll Weevil." Al- 

 though this investigation was motivated by 

 economic considerations, it is a thoroughly 

 sound and stimulating analysis of biological 

 control, i.e., control of the boll weevil popu- 

 lation by predatory and parasitic competi- 

 tion. In an attempt to evaluate these 

 predatory and parasitic pressures, the au- 

 thors reach these major conclusions (pp. 94, 

 95): 



1. "The control of the boll weevil by insect 

 enemies is sufficiently great to give it a 



high rank in the struggle against the pest. 

 A considerable portion of the insect con- 

 trol would not be accomplished by any 

 other factor; hence it is by no means to 

 be neglected." 



2. "The amount of control due to the var- 

 ious factors at work in any given place 

 should be increased if possible. Parasites 

 can be introduced into new fields." 



3. "The parasites and predators which at- 

 tack the boll weevil are native insects, al- 

 ready present in a given territory before 

 the weevil arrives." 



The synecological distinction of this paper 

 lies in the authors' constant emphasis on 

 interspecies relationships, whatever the 

 type. This is climaxed in an interesting dia- 

 gram that attempts to put in simple form 

 all the major relationships unearthed. Be- 

 cause of the novelty of this figure and 

 because it presages much that is to come 

 later in this book, it is reproduced on page 

 53 (Fig. 1). 



The microfauna was not neglected dur- 

 ing the decade 1911 to 1920. Waksman 

 (1916) wrote cogently of it in a paper 

 entitled "Studies on Soil Protozoa." He dis- 

 cussed three aspects: (1) active protozoan 

 fauna in the soil; (2) numbers and types of 

 Protozoa in different soils at difi^erent 

 depths; and (3) the effect of Protozoa on 

 bacterial numbers and their decomposi- 

 tion of organic matter in the soil. His two 

 major conclusions were that moisture, hu- 

 mus content and soil structure are the most 

 important factors to which soil Protozoa 

 react, and that soil Protozoa reduce 

 bacterial numbers. In reference to the lat- 

 ter statement, Waksman makes the point 

 that, when conditions become favorable for 

 the Protozoa, the bacteria decrease. Pre- 

 sumably, this effect is competitive in 

 character, although Waksman did not ana 

 lyze it in any detail. 



At this point attention should be called 

 to a considerable, early twentieth century 

 "Cornell School" of naturalists, including 

 A. A. Allen (Ornithology), A. H. Wright 

 (Vertebrate Zoology), and James G. Need- 

 ham (Entomology and Limnology), with 

 their students, and with the addition of 

 W. J. Hamilton (Mammalogy) in 1926 

 Cornell had become the center of entomo- 

 logical research and education imder the 

 influence of John Henry Comstock (1849- 

 1931), and of interest in vertebrate zoologv 

 under Burt G. Wilder (1841-1926). "Field 

 Zoology" flourished at Cornell in the varied 



