Chap, iv.] , OF ALIMENTS. 469 



It is still more unwise to fix the attention exclusively on one 

 alone of the nutritive acts of the plant, to take account only of 

 the decomposition of the carbonic acid. No doubt the chloro- 

 phillian plant dissevers the elements of the carbonic acid ; no 

 doubt, moreover, the chlorophillian function depends strictly on 

 the solar light, and we have a right to regard the labour accom- 

 plished by the chlorophillian cell as a dynamic transformation of 

 the radiation of the sun. But the decomposition of the carbonic 

 acid does not represent all the labour effected by the green parts 

 of plants. These organs are assuredly apparatus of organic 

 synthesis, laboratories where are found at the same time both 

 ternary compounds and quaternary compounds. M. G. Ville ^ 

 has shown that seeds sown in calcinated sand and watered with 

 distilled water, and cultivated in a receiver with glass walls 

 yields an excess of azote at the time they have ripened and are 

 gathered. Nevertheless he had added to the sand in which the 

 roots grew nothing but phosphate of lime, some potash, some 

 lime, oxide of iron, sulphate of lime. Moreover, the same 

 experimentalist found normally an overplus of azote in many of 

 our domestic plants when gathered. Finally, he was able to 

 conclude from his observations and experiments, that during 

 germination any vegetal needs to find within reach a certain 

 provision of azote completely prepared. It is in their cotyledons 

 that certain species, for example the leguminosae, take this 

 quantity of azote, this azote of development. As to the plants 

 less fortunately endowed, they need to find in the soil, in the 

 form of manure, the azote which is indispensable to them, and 

 which they are powerless to procure otherwifie. But when the 

 germination is terminated, when the plant is furnished with 

 chlorophillian leaves, it assimilates direct azote taken from the 

 grand atmospheric reservoir. It is then that it forms by 

 synthesis both the starches and the albuminoidal substances 

 which it needs for growth and reproduction. That the green 



1 G. Ville, Assimilation de V Azote pctr Us Plantes {Bemie Sdentifique, 1866, 

 No. 8). 



