Chapter XLIV. 



Maintenance of the Plant Individual. 



Like every other living thing the plant must maintain itself 

 or die. For different kinds of plants the normal duration of 

 life may greatly vary. Thus, the microscopic females of cer- 

 tain orchids, hidden, as they are, deep within the rudimentary 

 seeds of their species, may exist for but a few days or weeks. 

 On the other hand, in the canons of the Sierra Nevada, there 

 still stand, challenging the winds and the winters of the cen- 

 turies, Sequoia trees that were saplings when the pyramids were 

 new, noble trees when Rome was in her glory, and already 

 giants of the western forest when Columbus set sail on an un- 

 known sea. 



Whether the life of a plant be long or short, it may be de- 

 scribed as arising and continuing through a series of adjust- 

 ments, complex, subtle, immemorial, between the forces and 

 the substances of Nature. The materials of which the plant 

 is made are certain ordinary chemical elements. Their num- 

 ber and their character can be determined by recorded methods 

 of analysis. The energy manifested by the plant in its assim- 

 ilative processes, in its growth, and in its movements is but a 

 transformation of the energy with which it is supplied through 

 its food arid through the warmth and illumination of the sun. 

 Yet it is impossible to reduce the living plant to the terms 

 of an equation in chemistry and mechanics. That this cannot 

 be done is because the plant is really a microcosm. The 

 problem of its existence is as difficult and as profound as that 

 of the universe. There it stands beside one's doorstep, humble, 

 passive and inarticulate. Yet it responds to the forces of 

 light and gravitation reaching it from the depths of infinite 

 space. It is touched by terrestrial dews and breeze, and, after 

 its fashion, reacts to such local stimuli. It is moulded by the 

 inheritance which comes to it through an ancestral line reach- 



