132 THE LIFE-BLOOD OF VEGETATION. 



But they were swayed by that egotistical instinct which 

 leads man to refer everything to himself, even the very gods 

 which he has created after his own image. The Bible 

 teaches us that there is but one God. Alas ! are there not 

 as many gods as there are men ? Does not each of us 

 create a deity in accordance with his own inclinations, his 

 mode of thought, his degree of mental culture, the sphere 

 of his ideas ? Is the God of a tolerant philosopher identical 

 with that of a bigoted fanatic ? It is not so much due 

 to a deceitful appearance, an optical illusion, as to a kind 

 of innate infatuation, that the human race have come to 

 consider the planet they inhabit as the centre of the universe. 



CAUSES OF THE CIRCULATION OF THE SAP. 



Let us return to the sap, the life-blood of vegetation. 



How is it that its movement does not recommence at 

 the same time in all plants? Why are some clothed with 

 leaves when the others are scarcely budding? Where- 

 fore, in certain genera, do the flowers appear before the 

 leaves ? 



Some authorities assert, but facts show it to be a purely 

 gratuitous supposition, that the flower, which, with the 

 fruit, seems to be the goal or object of vegetation, demands 

 a greater activity on the part of the sap. But, in truth, 

 many trees and shrubs, such as the poplar, the willow, and 

 the hazel, flourish at an epoch when the sap is barely aroused 

 from its protracted lethargy. 



