CHAPTER III 



THE PRINCIPLE AS MANIFESTED IN 

 THE VEGETABLE KINGDOM 



As both the animal and vegetable kingdoms are, without 

 doubt, governed by the same biological laws, our principle 

 should apply to the latter as well as to the former, though 

 clearly not in its present form, as plants possess, so far 

 as is known, no nervous energy. But the function of 

 the nervous system in animals appears to be fulfilled 

 in plants by protoplasmic extensions connecting cell with 

 cell, and, as the functions of the various parts of a plant 

 are mutually co-ordinated, we must assume the presence 

 of some co-ordinating factor. Otherwise we should have 

 an effect without a cause. If this factor should at any 

 time be located, it will take the place in our formula 

 occupied by nervous energy. In the meantime we may 

 substitute the term " vitality " as expressing that general 

 vigour of growth which springs from a favourable com- 

 bination of circumstances. 



The variation of the degree of vegetable fertility in 

 response to the direct action of the environment will bear 

 an inverse proportion to the development of vitality. 



This term will be sufficiently precise for our purpose, 

 but the principle will need an important qualification. 

 It is clear that in an environment that is absolutely 

 barren and devoid of nourishment no seed will be pro- 

 duced. Seed will only be produced where there is a 

 supply of nutrition, as Nature does not make bricks 



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