POSITION OF ECOLOGY IN MODERN SCIENCE 183 



of Lagoa Santa, in Brazil, also that of Juan Fernandez and the 

 division of Mt. Kinabalu, in Borneo, into regions, quickly bore 

 the methods of the doctrine of formations to distant lands, whose 

 floras until then had only been known to us through the systematic 

 enumeration of their orders. Thus the way was prepared for the 

 recognition of ecology as a new and special centre, and scarcely ten 

 years have elapsed since this centre, which would unite biology to 

 the natural sciences, was demanded. 



Whoever wished to pursue the study of the physiology and devel- 

 opment of organs, in order to understand the weapons used in the 

 struggle for space on land or in water; whoever wished to study the 

 mutual relations of species, rather than their inherited character- 

 istics, or to consider the flora and fauna not only as they determine 

 the characteristic appearance of the country they inhabit, but also as 

 being the external, vital result of the effect of geographical factors, 

 which is capable in its turn of influencing the aspect of nature, had 

 to be called an ecologist, whether he wished to be so designated or 

 not. Even the name of this new branch of science was still in dispute 

 and no one was satisfied. To-day, however, we need not concern 

 ourselves with the name. From the beginning, the mutual relations 

 existing between the various branches of science exerted upon 

 ecology the powerful influence which usually only accompanies the 

 gradual change from the purely scientific to the utilitarian point of 

 view. 



In this historical sketch we have now reached the fifth period, 

 which begins with the publication of MacMillan's well-known study 

 of the Lake of the Woods (1897) and Warming's Lehrbuch der okolo- 

 gischen Pftanzengeographie. These works emphasize the special pro- 

 vince of ecology and give preference to the methods employed in 

 the organic natural sciences rather than to those used in the geo- 

 graphical. It soon appeared as if this daughter of bio-geography 

 would destroy the reputation of her mother and usurp her place, 

 but the opportune appearance of Schimper's work, based upon the 

 same foundation and fulfilling Grisebach's unattainable dream, 

 completely restored the connection between the highly specialized 

 ecological and the broader geographical points of view. The most 

 distinguishing characteristic of this last period, however, is the 

 closer bond of union established between ecology and phylogeny. 



Evolutionary thought, which is the keynote of modern natural 

 science, may proceed along two lines: according to the variation 

 of species in regard to their spatial requirements, or according to 

 the variation of an association under the influence of successive gen- 

 erations, each of which has undergone modifications. In this way 

 the study of phylogeny is extended to the field of floristic geo- 

 graphy. The connection between these two lines of thought will be 



