32 VICTOR E. SHELFORD. 



served its purpose or sh<>\\- it- defects. It is not, however, the 

 only method of ecology . and it should not be employed alone, but 

 accompanied by experimentation. 



This same method may be employed in the study of the 

 historical problems of biology, or to the study of evolution, but 

 the results are not ecology because this method is employed. Nor 

 is there any intimate dependence between the fundamental things 

 in ecology so far as its progress as a science is concerned, and the 

 di\ isions of biology known as evolution, morphology, or faunistic 

 geography. 



Physiographic analysis is only a part of a more general method 

 of deducing succession and laying a foundation for comparisons. 

 The general method of successional study has a probable sig- 

 nificance which lies beyond the recognition of the physiological 

 characters of organisms as a whole and the analysis of organisms 

 as far as the method will permit. 



(c) The Significance of Succession. 



It will be noted that in the above statement of succession no 

 reference to species is made. Species in the morphological sense 

 can have only the most local significance in succession. Species 

 inhabiting similar stages in the physiographic succession of 

 streams, i. e., similar conditions will hardly be the same within 

 a very small area. It appears that the idea of succession has 

 been regarded as having little significance for this reason. A 

 point of significance is the character of the -mores. In the matter 

 of their mores the fish communities of a stream in Europe, a 

 stream in Japan, and a stream in the United States are probably 

 similar if the streams are similar a matter for experimental 

 \ erification. 



A science with only one method of classifying its data must 

 constantly fall into error. Up to the present we have but one 

 organized general system of classification for zoological material-, 

 namely taxonomy. Taxonomy has been over-emphasized and 

 carried into fields where it does not properly belong. It has given 

 us, among oilier things, what has been called composite natural 

 history. Composite natural history constitutes a large part of 

 the natural history of today, e-peciall\ as contained in general 

 \\orks on natural history. The dc\ rlopment of a composite 



