POSITION OF ECOLOGY IN MODERN SCIENCE 185 



tigation of the ecological station and the analysis of the smallest 

 associations. The union of the morphological, geographical, and 

 phylogenetic points of view upon the physiological basis of adapta- 

 tion and dependence, alone gives us the essence of ecology. There- 

 fore we will devote the following remarks to an elucidation of these 

 three fundamental ideas, and try to show how intimately their 

 connecting threads are interwoven. 



(1) Considering the many internal and external differences in the 

 adaptation of various organs to the environment shown by aquatic, 

 rock-living, forest, and swamp plants, or springing, flying, creeping, 

 and swimming animals, it has been thought expedient to elaborate 

 this point of view separately, which serves as a basis for physiolog- 

 ical anatomy. The works of Schwendener, Vesque, and Haberlandt, 

 which turned the methods of systematic, anatomical description into 

 physiological channels, gave botany its freedom. Yet it is difficult 

 to develop a special ecological system of instruction from morphology 

 and anatomy alone, since an inextricable network is formed by the 

 relations existing between inherited systematic structure, climatic 

 factors, regional peculiarities, and the influence of coexisting plants 

 and animals, whether friends or foes. 



Each one of these relations is capable of forming a basis for com-, 

 parative analysis and classification. The dissatisfaction felt with 

 earlier as well as with more recent divisions, such as those given in 

 Reiter's Consolidation der Physiognomik (1885), is explained by 

 the inconsistencies which necessarily attend the incessant change 

 from morphological to physiological or physiographical character- 

 istics, and it is doubtful whether we shall ever be able entirely to 

 avoid them. The difficulties are most apparent when we attempt 

 to change the accustomed systematic arrangement of our museums 

 to one which shall represent the ecological features of a given forma- 

 tion. It is, however, necessary to work out this new point of view, 

 using ecological types as a basis. 



There are quite a number of individual morphological forms 

 having no definite ecological meaning; undershrubs, shrubs, and bulbs 

 are found distributed in the most dissimilar stations in every clime, 

 while their requirements in regard to season, warmth, and light 

 differ totally. Undoubtedly the most important forms of vegetation 

 are those which depend directly upon the climate and whose appear- 

 ance typifies to the geographer, unversed in ecological methods, a 

 certain definite landscape. Von Humbolclt tried to do justice to 

 the importance of these forms when he made the first attempt at 

 classification. 



The principles of ecology have been of especial value in the intro- 

 duction of ecological names, which refer to annual periodicity, such 

 as "evergreen leather-leaf plants," "trees bearing a tufted, ever- 



