THE CANADIAN ENTOMOLOGIST 111 



Animal Communities in Temperate North America, as il- 

 lustrated in the Chicago Region. By Victor E. Shelford, In- 

 structor in Zoology in the University of Chicago. The Uni- 

 versity of Chicago Press. 380 pages. 8vo. cloth, $3.22, 

 postpaid. 

 Until the beginning of the present century the study of animal 

 ecology can scarcely be regarded as having been an organized 

 science, and, although much has since been written upon the sub- 

 ject, most of the literature deals with problems of a more or less 

 specialized character, or with particular groups of forms or types 

 of locality. 



The present work is of an unusually broad scope, treating, as 

 it does, practically all the important types of animal communities 

 represented in the Chicago district, the total area investigated 

 being somewhat more than 10,700 square miles. It is a work of 

 great interest and importance to the entomologist, as well as the 

 student of general ecology, as insects play a dominant part in 

 practically all of the land and fresh-water animal communities. 



The first four chapters form an introduction to the study of 

 animal ecology in general and to that of animal communities in 

 particular. Chapter I deals with the general subject of the struggle 

 in nature, the effect of man's relation to nature and the production 

 of secondary or man-made communities, as distinct from primary or 

 primeval communities. In Chapter II the general subject of 

 ecology is discussed. The author emphasizes the "inadvisability 

 of attempting to organize ecology on the basis of structure, as 

 structural changes resulting from stimulation by environment are 

 rarely of advantage or disadvantage to the animal, and the 

 structure of motile organisms is not readily modified by the en- 

 vironment." It is the activities of animals that form the basis for 

 the organization of ecology, not the mosphological characters of 

 the species, which are ecologically of little or no significance. The 

 subject of animal communities and biota is also discussed at some 

 length and a classification of communities is given. The chapter 

 concludes with a classified list of the chief animal communities of 

 the area investigated. 



In Chapter III an analysis is given of the factors that enter 

 into the composition of the animal environment. This includes a 



