23 



CHAPTER IV. 



OF THE CELLULAR IXTEGUMEXT. 



Immediately under the Cuticle we find a 

 succulent cellular substance , for the most 

 part of a green colour, at least in the leaves 

 and branches, which is called by Du Hamel 

 the Enveloppe cellulaire, and by Mirbel the 

 Tissu herbacL This is in general the seat 

 of colour, and in that respect analogous to 

 therete mucosum, or pulpy substance situated 

 under the human cuticle, which is red in the 

 European, and black in the Negro; but we 

 must carry the analogy no further, for these 

 two parts perform no functions in common. 

 Du Hamel supposed this pulp to form the 

 cuticle ; but this is improbable, as his expe- 

 riments show, when that membrane is re- 

 moved, that the Cellular Integument ex- 

 foliates, at least in trees, or is thrown off in 

 consequence of the injury it has sustained, 



