Chap, i.] • OF NUTEITION. 87 



If a tissue is at the same time constituted by cells and furnished' 

 with a rich vascular network, it is in conditions specially favour- 

 able, and the nutrition thus is rapid and energetical : this is 

 what takes place in the mammifers, in the medullary tissue of 

 the bones, in the grey substance of the brain, and so on. 



After the exposition of the general facts to which we have 

 devoted this chapter, it will be now more easy for us to 

 present successively in the two organic kingdoms the history of 

 nutrition, that is to say, of the vital property which is the 

 support and the essential cause of all the others. 



