RECENT KESEAECHES ON THE BESPIEATION OF PLANTS. 223 



that ever since 1849 {Ann. des Sci., 1850) I was inclined to 

 regard what was called the respiration of leaves as two distinct 

 processes. 



Plants decompose water and lix its hydrogen ; they decompose 

 ammonia and its salts, and fix nitrogen ; they reduce sesqui- 

 oxide of iron in solution to protoxide, and they reduce carbonic 

 acid obtained from the soil, formed in their tissues or taken from 

 the air. All these acts are, in our opinion, closely connected 

 with the functions of assimilation and nutrition, whilst the con- 

 sumption of carbon and perhaps other elements, which is the 

 principal source of the vital heat of plants, is connected rather 

 with the function of respiration. If we look, then, at the most 

 evident phenomena, the respiration of plants does not differ from 

 that of animals, and instead of tlie processes being different in 

 flowers, leaves, fungi, &c., they are all identical, combustion of 

 carbon and production of heat, which may itself influence the 

 intensity of the function of respiration, where only a small quan- 

 tity of the acid produced thereby escapes reduction. 



The existence of a diurnal and nocturnal animal respiration in 

 plants ought not to be looked upon as very surprising if it be 

 remembered that those matters whose vital properties are most 

 manifest in plants have life, and are of an animal nature, and, it 

 may be added, become true animals at certain periods of the life 

 of some plants. 



Let us take for example the animalcules found in the anthe- 

 rida of Chara, Nitella, Ferns, Mosses, Horsetails, Liverworts, 

 t&c., which have been so carefully examined by MM. G. Thuret, 

 Niigelli, Sumenski, Wigand, Derbes, Sollier, «S:c., and it will 

 be found that their animal nature cannot be doubted, and that 

 their origin is incontestably owing to tlie metamorphoses or de- 

 velopenient of the living proteine substances of the cells. For 

 my own part, I have observed them in several species of Chara, 

 in Nitella jiexilis, and Marchantia polymorpha, and the animal 

 nature of these beings appears to me so evident that, with all due 

 respect to M. Siebold, I cannot help thinking that his observa- 

 tions were made at a wrong season. 



Let us examine again the motion of the zoospores, discovered 

 by Meyen, and the organization of which was described by 

 linger in the Vaucheria clavata, and afterwards by Thuret, and 

 the movements of the sporoides of different Fucacem described 

 by MM. Decaisne and G. Thuret {Ann. des Set., 1850) ; and if 

 we do not then believe the living azotized substances which move in 

 the cells of plants to have the organization of animals (as, for 

 example, that of the animalcules in the antheridia, or of the 

 zoospores), we shall be at least convinced that their organizations 

 are remarkably similar. 



