THE PROBLEMS OF ECOLOGY 195 



but it was quickly found that the term biology, already overloaded 

 with meanings, would prove but poorly distinctive in this applica- 

 tion, and the name ecology was substituted. 



It is easy to understand the rapid growth of the subject. The most 

 attractive phenomena of nature were awaiting its reclassification. 

 The speculative biologist had done much to clarify ideas upon the 

 evolutionary history of the vegetable kingdom. The unspeculative 

 histologist and physiologist had been accumulating a great wealth 

 of facts, which were ready at hand to be correlated by broad and 

 interesting generalizations. Systematic botany added its well-nigh 

 boundless literature regarding the affinities and diagnostic features 

 of plants. Conditions were all favorable. 



One of the greatest difficulties of the ecologist has been to find a 

 simple basis of classification for the phenomena covered by his sub- 

 ject. Their great diversity has made it hard to group them in a logical 

 system. Their common element is too slight to suggest a consistent 

 arrangement. It is true, ecology can in a very broad way be divided 

 into the relations of plants to their inorganic environment, to other 

 plants, and to animals; but this does not go far toward a satisfactory 

 classification. The clearest and by all means the best basis for the 

 grouping of ecological facts is their geographic aspect. As has been 

 already mentioned, there are few if any ecological modifications of 

 plants which cannot be in some way correlated with their habitat. 

 It is in this way that ecology has now become inextricably merged 

 into phytogeography, and that phytogeography enriched by ecolog- 

 ical methods has become one of the most attractive and promising 

 fields of botanical research. 



Having thus endeavored to make clear the general nature and 

 origin of ecology, together with its historical relation to phytogeo- 

 graphy, I may proceed to their joint problems, treating henceforth 

 the two subjects as coextensive and forming but a single discipline. 



The examination of plant life from a new point of view necessitated 

 to a great extent a new nomenclature. All ecological phenomena, and 

 especially every phase of plant distribution, had to be reexamined 

 in a detail which could not be technically expressed by existing 

 words. Old terms were redefined and new ones invented in bewilder- 

 ing succession. This nomenclature is still inchoate, for the growth 

 of interest in ecology has been so sudden that there has been no time 

 for its language to become fixed by usage or for any survival of the 

 fittest to determine which of its many synonymous terms will prevail. 

 There are at present two general practices or tendencies apparent. 

 Many of the most critical and effective writers on plant relations have 

 contented themselves with a small number of new terms. In express- 

 ing a novel idea for which no technical term was at hand, they have 

 avoided coining one, and have used instead some descriptive phrase. 



