48 NUTRITION. 



animal fibrine, vegetable albumen and animal albumen, 

 hardly differ, even in form ; if these principles be want- 

 ing in the food, the nutrition of the animal is arrested ; 

 and when they are present, the graminivorous animal 

 obtains in its food the very same principles on the pres- 

 ence of which the nutrition of the carnivora entirely 

 depends. 



Vegetables produce in their organism the blood of all 

 animals, for the carnivora, in consuming the blood and 

 flesh of the graminivora, consume, strictly speaking, 

 only the vegetable principles which have served for the 

 nutrition of the latter. Vegetable fibrine and albumen 

 take the same form in the stomach of the graminivorous 

 animal as animal fibrine and albumen do in that of the 

 carnivorous animal. 



From what has been said it follows, that the devel- 

 opment of the animal organism and its growth are de- 

 pendent on the reception of certain principles identical 

 with the chief constituents of blood. 



In this sense we may say, that the animal organism 

 gives to blood only its form ; that it is incapable of 

 creating blood out of other substances which do not al- 

 ready contain the chief constituents of that fluid. We 

 cannot, indeed, maintain, that the animal organism has 

 no power to form other compounds, for we know that it 

 is capable of producing an extensive series of com- 

 pounds, differing in composition from the chief constitu- 

 ents of blood ; but these last, which form the starting 

 point of the series, it cannot produce. 



The animal organism is a higher kind of vegetable, 



