THE DOCTRINE OF VITAL UNITY. 155 



sugar, and this reserve stuff is distributed throughout 

 the stalk after having been digested, exactly as would 

 have been the case in the digestive canal of man. 



Vegetables, then, really digest. The four classes of 

 substances mentioned above are really digested in 

 order to pass from their actual form, a form unsuitable 

 for interstitial exchanges, to another form suitable for 

 nutrition. As there are four kinds of foods, so there 

 are four kinds of digestions, four kinds of ferment- 

 producing agents-^amylolytic,^ proteolytic,^ sacchar- 

 ine, and lipasic^ diastases, identical in the animal 

 and the plant. Identity of ferments implies identity 

 of digestions. Going down to the very basis of 

 things, the digestive act is nothing but the action of 

 this ferment. This is the crux of the whole question. 

 All else is only difference in scene, varying in the 

 means of execution and in the accessories. The 

 difference arises from the stage on which it takes 

 place, but the piece which is being played is the 

 same, and the actors are the same, and so is the 

 action of the play. 



This identity between animal and vegetable life is 

 found in the phenomena of respiration and of motility. 

 The limits of this book do not allow of our entering 

 into the details of facts. Besides, the facts are well 

 known, and may be found in any treatise on general 

 physiology. This science, therefore, enables us to 

 perceive the imposing unity of life in its essential 

 manifestations. 



^ Amylolj'tic ferments change starch and glycogen {ainyloses) 

 into sugar. — Tr. 



■^ Proteolytic ferments change proteids into peptones and 

 proteoses. — Tr. 



' The enzyme known as lipase splits the fat or oil in germ- 

 inating seeds into a fatty acid and glycerine. — Tr. 



