THE CUTICLE AND EPIDERMIS, 61 



cellules broken by raising the epidermis. Hedwig, 

 Kieser, and Amici, among the moderns, have maintained 

 the first opinion. Kroker, Mirbel, Link, Sprengel, and 

 Rudolphi, have more or less adopted the second ; and I 

 have myself coincided with them in my former works. 

 From new observations, and a more attentive regard to 

 known facts, I have been led to the idea that the two 

 theories are both quite true, but applicable to different 

 organs; and that all the contradictory arguments of 

 anatomists are true as concerns one part of the organs, 

 but false with regard to the other. 



I admit, then, that the epidermis of leaves, and most 

 probably that of all annual shoots, is not a peculiar mem- 

 brane, (as Grew, who called it Cuticle, considered,) but 

 a particular layer of cellular tissue very distinct from 

 all the following, constituting also a kind of covering 

 which I also call Cuticle ; for the name Epidermis, 

 which signifies a scarf-skin, does not apply to it, since it 

 constitutes of itself the entire skin : on the contrary, 

 in old stems, the membrane, or membranes, which are 

 formed upon the bark, are only the external cellules 

 dried b}^ the air ; these may retain the name Epidermis, 

 since the cellular envelope, which is beneath, performs, in 

 certain respects, the function of the skin. 



In examining these two organs, we shall at once give 

 both their description and the causes of our opinion; 

 and, consequently, we shall discuss the reasonings for 

 and against the two theories. 



