682 THE POPULAR SCIENCE MONTHLY. 



disturbances of a deeper and universal state of forced equilibrium, 

 which pervades the vital as it is known to pervade the mechanical 

 world. And just as astronomers aud physicists, confining their inves- 

 tigations to the more obvious and perceptible motions of celestial and 

 terrestrial bodies, long remained ignorant of the law of gravitation 

 which constantly forces all things into a state of equilibrium, so in 

 biology the statical condition has been lost sight of in the effort to 

 obtain better views of that moving panorama which a broader knowl- 

 edge of the phenomena of life so unmistakably unfolds. Yet, without 

 a clear recognition of this statical law, it is impossible to account for 

 the facts presented by the distribution of plants, and it will doubtless 

 be found equally essential to the full comprehension of many other 

 phenomena of Nature. But, when we recognize this law, the whole 

 aspect of our question is changed. Plants appear to be no longer in 

 a state of perfect adaptation to their surroundings. 



There is no longer a necessary correspondence and correlation be- 

 tween organism and habitat, no longer necessary that rhythmical 

 (almost preestablished) harmony between species and environment. 

 This need only exist so far as is necessary to render the life of the 

 species possible. Beyond this the greatest inharmony and inadapta- 

 tion may be conceived to reign in Nature. ' Each plant may be re- 

 garded as a reservoir of vital force, as containing within it a potential 

 energy far beyond and wholly out of consonance with the contracted 

 conditions imposed upon it by its environment, and by which it is 

 compelled to possess the comparatively imperfect organization with 

 which we find it endowed. Each individual is where it is, and what 

 it is, by reason of the combined forces which hedge it in and deter- 

 mine its very form. Each species is the perpetual and inexorable 

 antagonist of every other. The "struggle" is not alone "for exist- 

 ence," it is also for place. In the plant races, as in the human, there 

 is a recognized hierarchy, the laws of which are as yet to a great 

 extent involved in mystery. But the first principle, as in the rest of 

 Nature, is force. Each one encroaches with all the power of vegetal 

 growth upon its neighbors. This pressure is enormous. Who shall 

 calculate this subtilest of molecular forces? Yet there is no displace- 

 ment, no motion. So thoroughly has every nook and chink been filled 

 that there is no room for motion. Like the all-pervading circumam- 

 bient air, its power is not felt so long as no vacuum is produced. 

 Each organism has long since reached the limit of its power to extend 

 its dominion. The plant grows up from the germ to maturity under 

 a constant surveillance, and every attempt to overstep its fixed limits 

 is instantly checked. It stands in its fixed position, locked in the 

 embrace of forces which permit it neither to advance nor retreat. 



Such is the state of equilibrium which is always and necessarily 

 reached in a state of Nature, and in which man first finds each newly- 

 discovered flora. But let these statical conditions be once changed, 



