180 ECOLOGY 



connected with the outer world. Animals that live alone, or are 

 banded together in flocks, swarms, or herds of the same species, 

 are naturally incapable of building formations dependent upon the 

 climate and inseparable from the soil. Their power of locomotion 

 is a hindrance to the close connection with Mother Earth that is 

 maintained by the flora. 



Ecology is new in name only, and while stress has lately been 

 laid upon the versatility of its special methods, we find the sources 

 from which they have been derived far back in the past century, 

 and the connection between ecology and geography, as evidenced 

 by the restriction of the animate world to stations with special 

 physiographic features, is expressed in the excellent floras of earlier 

 days. Linnaeus, in his Flora lapponica, a work which until recently 

 has hardly received due recognition, has given us an example of how 

 a flora may not only give a diagnosis of the different species, but 

 also a description of their mode of life. A flora containing a descrip- 

 tion of the methods employed by the most widely distributed plants 

 in perpetuating their existence, unfolding their blossoms, and ripen- 

 ing their seeds, is of the utmost importance for the true comprehen- 

 sion of the part played by every species in covering the soil with 

 verdure. The worthy florists of that early period undoubtedly recog- 

 nized the fact that the appearance of similar associations followed 

 definite laws which they endeavored to express in the terminology 

 used in their diagnosis of the situation; thus they actually were the 

 founders of the modern doctrine of "plant formations." 



But in order that ecology should advance to the rank of an inde- 

 pendent branch of science capable of further development, the 

 creative genius of an investigator was needed, who, unsatisfied by 

 the older methods of description, could work from a more general 

 basis. During his long journeys through distant lands, Alex, von 

 Humboldt had recognized the special scientific value of the mutual 

 relations existing between the annual change of season and the form 

 of vegetation assumed by predominating plants. Accordingly, he 

 chose a few representative orders of the plant kingdom, fifteen in 

 number, such as palms, conifers, cacti, tree-ferns, mosses, and lichens, 

 which by their mode of growth and perennation give a certain de- 

 finite physiognomy to the district in which they predominate, since 

 each one of these groups gives rise to landscapes totally differing 

 in character. Von Humboldt was undoubtedly guided by the 

 ecological spirit, as we should say to-day, in the elaboration of his 

 excellent system, whose defects lay in the then existing confusion 

 of vegetative form with systematic character. 



Alphonsc de Canclolle enumerated these defects, when, in his 

 Geographic botanique raisonnee, he laid the foundation upon which 



