FIRST FOUR DECADES OF THE TWENTIETH CENTURY 



47 



he discussed the North Atlantic ocean, 

 types of life in the sea, including notes on 

 fishes and fishing; in the second part he 

 stressed the quantitative method as applied 

 to plankton census and productivity; and in 

 the last part he dealt with the "metabolism 

 of the sea"— food relationships, bacteria, and 

 nitrogen circulation. Even to a modern 

 worker the book is a sound contribution. It 

 is safe to assume that its impact on aquatic 

 ecology was considerable. 



Ostenfeld's paper was important, since it 

 showed clearly "... the controlling rela- 

 tion of marine vegetation upon animal 

 associations and particularly the fish of the 

 coast of Denmark" (Adams, 1913, p. 89). 

 Work of this type indubitably helped to 

 draw together plant and animal ecology. 

 Sumner's paper is an excellent example of 

 a certain type of field study. The bottom 

 fauna and flora of an area around Woods 

 Hole, Massachusetts (namely. Buzzards 

 Bay and Vineyard Sound), were studied in 

 relation to temperature, character of bot- 

 tom, depth, saUnity, and density. The local 

 distribution of each species was carefully 

 determined and mapped. Conclusions were 

 drawn as to wliich factors were most im- 

 portant in shaping the observed distribu- 

 tions. In addition, the author formulated 

 some opinion about the geographical origin 

 of the fauna of the region. 



Fresh-water ecologists or hmnologists also 

 were making rapid strides during the first 

 decade of the twentieth century. This pe- 

 riod prospered under the influence of F. A. 

 Forel (1841-1912), a professor in the Uni- 

 versity of Lausanne, who has been called 

 the "founder of modern limnology." In 1901 

 Forel published his Handbuch der Seen- 

 kunde. Allgemeine Limnologie. The impor- 

 tance of this volume is well indicated by 

 Welch (1935, p. 5) in these words: "This 

 book is the first general presentation of 

 limnology from the modern standpoint. In 

 fact, it might well be termed the first text- 

 book of limnology. In brief, hmnology is in- 

 debted to Forel for the first knowledge con- 

 cerning the profundal fauna of fresh-water 

 lakes, for the first program for limnological 

 investigations of such waters, and for the 

 execution of such a program, resulting in 

 'Le Leman,' which was long a model for 

 subsequent work." 



A first-rate paper by Kofoid (1903) on 

 the plankton of the Illinois river was a de- 

 tailed, meticulous study with a definitely 



ecological point of view. In 1904 E. A. 

 Birge published a paper in which he clearly 

 demonstrated thermal stratification in in- 

 land lakes and formulated a standard 

 method of expressing it. In a historical dis- 

 cussion one is tempted to pause over the 

 names of Birge and his colleague Juday to 

 pay tribute to their cogent contributions to 

 aquatic biology. Another book that seems 

 to have been important during this decade 

 was that by Knauthe (1907). 



There is some point in dealing specifically 

 with ecological succession. This was the era 

 when plant ecologists were interested in the 

 phenomenon. The animal ecologist was 

 starting his investigations on succession, to 

 be followed actively in the next ten years. 

 Cowles published his "Sand Dunes" paper 

 in 1899. This stimulated the zoologists 

 V. E. Shelford and C. C. Adams, who were 

 ecologically inclined from their association 

 with Davenport at the University of 

 Chicago, to examine the concept from a 

 zoological aspect. In 1907 Shelford reported 

 on the succession of tiger beetles {Cicin- 

 dela) in the same dunes region where Cow- 

 les had studied. He " . . . traced the rela- 

 tion of Cicindela to the succession of plant 

 communities. The distribution of eight spe- 

 cies of tiger beetles was in close correspond- 

 ence with the zoned habitats and communi- 

 ties, and the conclusion was reached that a 

 similar harmony existed with respect to the 

 fauna in general" (Clements and Shelford, 

 1939, p. 8). 



Adams' 1909 paper shows even more 

 respect for the concept of succession 

 than does Shelford's. It starts with this in- 

 teresting quotation from John Stuart Mill: 



"Of all truths relating to phenomena, the 

 most valuable to us are those which relate to 

 their order of succession. On a knowledge of 

 these is founded every reasonable anticipation 

 of future facts, and whatever power we pos- 

 sess of influencing those facts to our 

 advantage." 



Adams reviews much of the background for 

 ecological succession current at that time. 

 He discusses general principles as well as 

 specific avian illustrations. From his studies 

 of the latter he reaches this conclusion (p. 

 134): 



"... Bird succession means a change from 

 the dominance of certain species or associa- 

 tions to that of others. Thus in the beginning 

 a slight change in abundance of a species may 



