6 NATURE AND RELATIONS OF BIO-ECOLOGY 



his suggestion \Yas practically lost to view for a generation or more. 

 A somewhat similar doubt arises in respect to Dahl's adoption of the 

 word biocenose from JNIobius, for it appears that Dahl employed the 

 term mostly as a synonym of zoocenose (1903, 1904). As indicated 

 later in some detail, Clements, Shelford, France, and Vestal realized 

 the significance of the biotic community more fully and more or less 

 independently, but the distinction of the biome as the basic concept 

 in climax and succession was first made in 1916. 



Since this time, there has been a slow but gradual recognition of 

 the importance of the concept, exemplified in particular on the animal 

 side by Shelford and his students, on the plant side by Phillips. For 

 the reasons already touched upon, it is not to be expected that this 

 will become the universal approach, and this is probably not desir- 

 able, since some problems require intensive analysis, such as is best 

 secured by working with plants or animals alone. If it becomes gen- 

 erally recognized that the investigation of climax and succession must 

 reckon with the biotic formation as the natural community unit, this 

 will insure the proper perspective and methods. Although of a sec- 

 ondary character, the historical development of the ideas set forth in 

 this volume is important in an understanding of the terms and con- 

 cepts presented. 



Mobius (1877). Under the title, "An oyster bank is a biocenose 

 or a social community," Mobius gave a detailed account of the ani- 

 mal life of an oyster bed as brought up by the dredge. He stated 

 that very few plants grew upon the banks, namely, a single Zostera 

 and some of the Florideae, while the desmids and diatoms of the 

 plankton served as food for the oysters. Each oyster bed was re- 

 garded to a certain degree as a community of living beings, a collec- 

 tion of species and a massing of individuals, and since science pos- 

 sessed no term for such a grouping, he proposed the word biocenose. 

 Space and food were held to be necessary as the first requisites of 

 every social community, even in the sea, and he clearly perceived that 

 changes of physical factors, and disturbances by man as through over- 

 fishing, often greatly modified the social group. 



There is little evidence that Mobius regarded the biocenose as 

 constituted by both animals and plants, though such an assumption 

 has long persisted in connection with the use of the term. The single 

 mention of plants, the emphasis upon their role as food, and the com- 

 prehensive discussion of the species of animals all tend to confirm 

 this conclusion. This is supported by Petersen's statement that 

 "Mobius has called the animals living on an oyster bank a biocenosis," 

 and he also employed the term as synonymous with animal community 

 (1913:32). As is shown in the next paragraph, Dahl likewise thought 

 to employ the word in the sense of Mobius, but without rendering his 

 own usage either very definite or consistent. 



