430 PLANTS AND THE ATMOSPHERE. 



and demonstrated it ; but the whole of it already lay in the thought of LaToisier, 

 ■when he wrots : *' Oi'ganisation, spontaneous motion, life, only exist on the surface 

 of the earth, in places exposed to light. It might be said that the fable of the 

 torch of Prometheus was the expression of a philosophical truth that had not es- 

 caped the ancients. Without light, nature was without life: she was dead and 

 inanimate ; a benevolent God, by bestowing light, has spread over the surface of 

 the earth organization, feeling and thought." 



Although, during the regular course of its existence, a plant accumulates organic 

 matter, there are, however, two periods when it loses this essential characteristic 

 and in which it conducts itself as do animals : these are at the commencement and 

 at the end of its life, when it germinates and when it reproduces itself. Every 

 seed, besides the embryo which maintains during long years the principle of life, 

 encloses a supply of organic matter destined for the early nourishment of the 

 growing plant. Thrown upon a warm moist soil it sprouts ; its radicle seeks in 

 the soil a point of support and liquid nourishment; the bud rises; the seminal, 

 leaves or cotyledons develope themselves, and the rudimentary plant is constituted 

 in virtue of its intrinsic and transmitted life. But, during this primary period, 

 the supply of matter accumulated consists of two pai'ts ; one is burned by a spe- 

 cies of respiration ; the other, undergoing complicated chemical actions, is carried 

 into the organs and fixed there by being made, a constituent part of them; Every- 

 thing takes place nearly as in aii animal, and without any intervention of light : 

 but, after this primitive phase, when the respiratory organs have gained their first 

 development, the plant waits for the rays of the sun in order to continue its evo- 

 lution, and as soon as these rays come to it, it turns towards them as if eager to 

 collect them, becomes green and begins, to end only with death, that decomposi- 

 tion of carbonic acid and that accumulation of matter which is its function, and so 

 to speak its predestination. 



In order better to study this period of the intrinsic life of the seed, M. Bous- 

 singault formed the happy thought of prolonging it, by indefinitely retarding the 

 action of light. The experiment was made upon peas in a soil destitute of 

 manure. After having germinated they continued to grow, giving birth to a 

 blanched, thin, and prostrate stem which perished without bearing seed. During 

 all this time they made use of the organic matters primitively contained in the 

 seed, and, as they dragged on their painful existence, gave these forth, little by 

 little, in order to prolong life. Finally, each plant had lost more than half the 

 carbon originally contained in the seed. "While this experiment was going on in 

 darkness, other peas sown at the same time were successively brought to the light. 

 Thenceforward, everything was changed, true life was developed, and the vege- 

 table, able at last to make use of the nourishment contained in the air, gained 

 daily, in the sun, nearly as much carbon as it had before lost in darkness. 



Everything in nature has its analogue ; plants in the seed and animals in the 

 egg appear to accomplish the same actions, and are formed in the same condition. 

 In both cases a mass of organic matter accompanies the germ ; the egg and the 



