THE LOCAL DISTRLBUTION OF PLANTS. 681 



In this theory of perfect natural adaptation, whether it be left to 

 stand upon its old teleological basis, or be placed, as some modern 

 investigators would place it, upon a genetic one, a very important 

 factor has been left out, viz., the influence which plants exert upon 

 one another. Adaptation, as the term is employed, is applied to a 

 supposed correlation between the plant and its inorganic environ- 

 ment ; and to this alone is attributed their entire local distribution. 

 But facts of the class above considered prove that this is not only an 

 inadequate explanation of such distribution, but that it is in many 

 cases no explanation at all, since they so generally disregard inor- 

 ganic conditions, and thrive equally well or better under entirely dif- 

 ferent ones from those which Nature furnished. Their distribution 

 must, therefore, be almost entirely attributed to some other condi- 

 tions; and to what other conditions are they subjected but to organic 

 ones, to those which they reciprocally impose upon each other ? It is 

 to these organic conditions, then, to the mutual influence of different 

 kinds of vegetation, growing, as it always does in a state of Nature, 

 in close local proximity and contact, that we must look for the chief 

 laws that control the local distribution of plants. 



The modification, therefore, of the adaptation theory, or rather 

 the substitute for it, which, in the light of these facts, I would pro- 

 pose might be called the law of mutual repulsion, by which every 

 individual, to the extent of its influence, repels the approach of every 

 other and seeks the sole possession and enjoyment of the inorganic 

 conditions surrounding it this mutual repulsion results at length in 

 a statical condition which is always brought about through the action 

 of the vital forces themselves, and which, as soon as reached, deter- 

 mines absolutely the exact place and degree of development of each 

 species and each individual. 



It is this statical condition which is apt to be lost sight of in the 

 modern philosophy of evolution. The modification of species, the 

 survival and advancement of some and the depauperating and extinc- 

 tion of others, all forms of variation and transmutation these are 

 dynamical phenomena, and only take place under the influence of dis- 

 turbing agencies. Changes of this kind are slow and secular, and lie 

 beyond the reach of direct observation, perceptible only to the eye of 

 reason on the closest comparison of large masses of dependent facts. 

 They, therefore, long escaped observation, and Nature remained until 

 recent times a sealed book with respect to them. What wonder, then, 

 that this still deeper and more occult law of biological statics should 

 have remained still longer undetected, or only dimly seen ? For, un- 

 derlying this dynamical movement in organized beings, there must 

 exist a universal statical condition throughout organic as throughout 

 inorganic Nature. 



The changes of which science has at length caught a glimpse can 

 be nothing more than the regular and cyclical or fitful and spasmodic 



