950 MINNESOTA BOTANICAL STUDIES. 



crude form by no means enters into the matter and a sufficiently 

 careful examination of all the manifold environmental, individ- 

 ual and historical conditions should, if the data were at hand, 

 suffice to lay at least the foundations for rational ideas of plant 

 distribution over limited areas. It becomes possible, therefore, 

 to connect directly plant distribution and the aspect of plant 

 formations on the one hand, with atmospheric, geologic, topo- 

 graphic and biologic conditions of the environment on the 

 other. Every landscape thus becomes a definite scientific 

 proposition for analysis and explanation by enlightened obser- 

 vation and judgment. 



That branch of biology which concerns itself with the 

 adaptations of organisms to their surroundings is, by the 

 modern school, termed ecology, this name having first been 

 applied by Haeckel. Until but recently manj^ writers especially 

 in Germany, have employed, somewhat erroneously the term 

 biology with a restricted significance, meaning to cover by it 

 what is now included under ecology. But this need produce 

 no confusion. The science of ecology is capable of extended 

 sub-classification and very definite fields may be delimited 

 within the general boundaries. Just as biology is broadly 

 subdivided into botany and zoology, so ecology naturally pre- 

 sents itself as plant-ecology and animal-ecology. Each of 

 these divisions, pursuing the system followed when the field of 

 botany or zoology is to be further classified, may be refined 

 according to the exact range of inquiry that is proposed. Thus 

 paleoecology might be defined as the science of adaptations of 

 fossil organisms — in so far as such adaptations might be brought 

 in evidence, — or economic ecology, treating of adaptations in 

 their relation to human interests, might be defined. Four 

 main divisions of the subject are not difficult to indicate. These 

 are as follows: 



1. Ecological morphology. — This is that branch of biological 

 science which has for its content the adaptational stuctures of 

 organisms Environmental influences as displayed in the ar- 

 chitectural reactions of the body come within its scope. 



2. Ecological physiology. — This must be defined as that 

 branch of biological science which treats of the adaptations of 

 bodily or organic functions to outward forces. Modifications 

 in function, and the laws of their origin and development, 

 under stimulus from without are the field of special study. 



