4 MICHIGAN SURVEY, 1908. 



field for useful and valuable activity in the study of habitat preference, 

 and the mutual relations of the associated species in given habitats. A 

 familiarity with the forms studied, under diverse circumstances, de- 

 velops a certain perspective which is a great help in preventing confusion 

 caused by minor and relatively insignificant details. 



The limited time spent in the present investigation did not permit 

 detailed studies of the interrelations of the organisms within the habitat, 

 either in their relation to the environment or to each other. In local 

 studies attention is usually given to detailed life histories rather than 

 to a deliberate study of their interrelations as members of a society. 

 The emphasis which is sometimes placed upon individual life histories 

 would lead one to expect that such histories could be assembled and 

 would give us the same result as if they had been studied as a society. 

 But the points of view are so different that such a result, although 

 theoretically possible, is unlikely to be obtained. At this time we only 

 wish to emphasize the fact that both methods should be used to secure 

 the best results. For example, in applying these principles to the study 

 of birds, the life histories of the dominant species of a society might 

 first be given special attention. Then the relations of the dominant 

 species to others of the association and to the environment may be deter- 

 mined and later on the subordinate kinds considered. This will involve 

 prolonged study in the field (and laboratory) of the habits of nesting, 

 feeding, rearing of young, etc., as influenced not only by other mem- 

 bex's of -the same species, but also by other species in the same habitat. 

 The same general method is applicable to other groups of organisms. 



3. Previous Biological Investigations upon Isle Royale. Previous to 

 the investigations by the Museum party in 190-4, (Euthven and others, 

 '06) there seems to have been very little study of the Isle Royale biota. 

 Several collections of plants and animals have been made, but very little 

 has been published about them. In 1848 W.. D. Whitney was "ornithologist 

 and botanist" for the government geological survey parties, and he pub- 

 lished a list of the plants found. (Foster and Whitney, '51, pp. 359-381). 

 Incidental mention is also made in these geological reports of the collec- 

 tions of animals (Foster and Whitney, '50, pp. 17, 51, 201; Jackson, '49. 

 pp. 423, 440, 441,) ; but, so far as known to the writer, no detailed reports 

 were published. 



So far as the vegetation is concerned, the most important source of 

 information is the maps of the Ives Linear Survey. Here the general 

 character of the forest, the extent of the swamps, and the underbrush 

 are indicated. Mr. Henry Gilman ('73), of Detroit, made two visits 

 to the island (one of which was in 1873), and his botanical and ethno- 

 logical collections were presented to Columbia and Harvard Colleges. 

 In 1890 Mr. F. E. Wood made a collection of plants from the vicinity- 

 of Rock Harbor and presented them to the herbarium of the Botanical 

 Department of the University of ]\Iichigan ; and in 1901 W. A. Wheeler 

 ('01) published a short paper on some plants taken on the northeast 

 end of the island. 



The invertebrate fauna found in the deep water off Isle Royale was 

 examined by Smith in 1871, and .a list of Coleoptera from Isle RoyaJe 

 was published by Hubbard and Schwarz ('78). The writer has recently 

 published a paper on certain phases of the problem of succession, as 



