44 



THE HISTORY OF ECOLOGY 



plant ecology per se, but to appraise this 

 field as it has provided fact and catalyst for 

 zoological developments. Specific relation- 

 ships will be pointed out further on, but 

 these generalizations emerge: 



1. The investigations of early plant ecol- 

 ogists were favored somewhat by the fact 

 that plants are essentially fixed geograph- 

 ically and not greatly subject to rapid 

 dispersal. 



2. Plant ecology, naturally enough, de- 

 veloped regionally according to the local 

 resources that could be exploited and 

 studied. 



3. Plant ecology gave an early and sig- 

 nificant orientation to animal ecology in 

 several ways: (a) It stressed the fact that 

 communities or complex natural popula- 

 tions exist over the face of the earth and 

 are subject to analysis. This gave a telling 

 impetus to animal synecology. (b) It crys- 

 tallized certain comprehensive ecological 

 concepts such as succession and thus sent 

 animal ecologists out into the field to see 

 if animals also furnished data to support 

 the concept, (c) It developed certain tech- 

 niques of field study that could be used 

 with but minor mocification by the zoolo- 

 gist, (d) It emphasized in an ecological 

 sense the fact that plants stand in an im- 

 portant relation to animals in terms of nutri- 

 tion, breeding, and shelter niches. And, 

 perhaps most important, (e) it gave psy- 

 chological stimulus around the turn of the 

 century by showing the zoologist that first- 

 rate botanists were investigating ecological 

 problems and getting results. In short, the 

 animal ecologist owes much to the plant 

 ecologist in a historical sense, and, on land, 

 he is still dependent on plant ecology for 

 much of his zoogeographic description. 



Our task now is to discuss the growth of 

 twentieth century animal ecology. We find 

 that by dividing the years from 1900 to 

 1940 into their four component decades, 

 we can consider each of these decades both 

 as a unit and as an interrelated part of the 

 whole pattern. This is not a completely 

 arbitrary treatment. A case can be made 

 for the point that, during this span, ten 

 years seemed to be about the actual interval 

 for certain types of work to materialize and 

 certain ideas to be synthesized Thus, there 

 is nothing really difi^erent between, say, 

 the years 1910 and 1911 or 1930 and 1931, 

 but there does appear to be a real histor- 

 ical difiEerence between 1900 and 1910 or 



1911 and 1920 in terms of the development 

 of animal ecology. 



Our treatment varies somewhat according 

 to the individuaUty of the decade in ques- 

 tion, but in general we hope to ask, and 

 so far as possible to answer, the following 

 four questions for each: 



1. What were the research focal points? 



2. Who were some of the leaders in the 

 research fields discussed? 



3. What was the historical impact of 

 the work of these men? 



4. What grew out of the decade that 

 seemed significant? 



The reader should keep in mind that the 

 absence of a favored name or citation in the 

 following pages does not necessarily signify 

 that it has been overlooked or deemed un- 

 important. It may mean just that, or, con- 

 trariwise, it may mean merely that there 

 is not enough space for its inclusion. It is 

 necessary to emphasize that in dealing 

 with the foregoing questions we are 

 sampling historical data, and that our 

 sample is not a random one, but is selected. 

 Accordingly, our cases are subject to bias, 

 as, for example, our overemphasis on Amer- 

 ican historical illustrations. From one point 

 of view this is poor technique with obvious 

 limitations. But from another aspect it is 

 sound, since it does permit us to present 

 our notions of what is significant and there- 

 by evaluate ecological history as we see it. 

 With these preliminaries we turn to the first 

 decade of the twentieth century. 



1900-1910 



During this period of ecological growth, 

 ecological investigations seem to have fallen 

 into the following categories: response phys- 

 iology, developmental and toleration physi- 

 ology, natural history, hydrobiology, suc- 

 cession, and general synecology. These did 

 not originate de novo with the turn of the 

 century. Most of them had antecedents in 

 earlier work, as we have shown. 



Response physiology, or ecological as- 

 pects of behavior, was studied actively dur- 

 ing this period. Davenport's "Experimental 

 Morphology," the second edition of which 

 appeared in 1908, was still shaping ideas 

 and new researches. This was the period 

 when "trial and error" behavior was much 

 in the scientific headlines. Jenning's classic 

 Behavior of the Lower Organisms (1906) 

 had a firm impact on ecological thinking. 

 It showed that environmental stimuli, even 



