1914 J Recent Literature. 121 



Ruthven, and Shelford's personal researches in ecology, ecological studies 

 in this country have heretofore related almost entirely to plants. Shel- 

 ford's status as a pioneer animal ecologist is therefore clear. The impor- 

 tance of the subject and his mastery of it are demonstrated by the book 

 herewith reviewed. 



The contents of ' Animal Communities in Temperate America ' may be 

 conveniently grouped in 3 categories, a general discussion of the animal 

 organism and its environmental relations (3 chapters), the nature of various 

 environments and an account of their inhabitants (11 chapters), and a 

 general summary and theoretical discussion (one chapter.) Ecology as 

 generally understood is the relation of organisms to environment. As 

 environment includes all living things with which a species comes in con- 

 tact as well as its inorganic surroundings, it is easy to see that ecology is a 

 very comprehensive science. In fact the impression one gathers from the 

 introductory chapters of Shelford's book is that ecology is only less broad 

 than biology as a whole. 



The science of ecology has one obstacle to struggle against, that is, the 

 impression that ecological papers often seem to be but an elaboration of 

 the obvious. The present reviewer must admit that this criticism is not 

 unfounded ; in fact the impression forced upon him by a pretentious ecolo- 

 gical pubUcation of some years since took the following form, somewhat 

 Hibernice, that it was a statement of things everyone knew in language no 

 one could understand. Ecologic terminology is not carried to an extreme 

 in Shelford's book. The statement of facts constituting part of the funda- 

 mantal knowledge of most biologists is necessarily included. A little 

 inspection, however, shows that the ecologist endeavors to get at the phy- 

 siological basis for the relations of animals to their environments. The 

 obvious, well it is obvious, but the why of the obvious, ah! there is where 

 the expert in ecology is needed. Everyone knows that black-fly larvse live 

 on the upper surfaces of stones in swift currents. Why they prefer this 

 habitat is not so well known. Besides the evident advantage of having a 

 plentiful supply of food constantly brought along by the stream, the eco- 

 logist has found that they cannot complete their Ufe history in the absence 

 of current. The pupa of the fly is 'oosely enclosed in a cocoon. It has 

 been found that without current the insect cannot make this cocoon, but 

 makes a shapeless tangle instead. Certain animals prefer sand that is less 

 shifting and is slightly darkened by humus. Some fishes can live in water 

 with only 1 cc. of oxygen per liter while others require from 6-14 cc. We 

 might enumerate other instances of scientific answers to various whj^s, but 

 sufiice it to say that ecology is a field that has long needed cultivation. It 

 has already produced valuable results but much remains to be done. 



The notes on bii'ds in this book consist largely of lists of the species 

 inhabiting various formations. There can be Uttle complaint about most 

 of these, but the statement on page 274 that " The Baltimore and Orchard 

 Orioles build elaborate nests on the shrubs," should be corrected. On 

 page 166 the scarcity of information on quantity of life on the land is 



