102 EPIDERMIS. [LECT. in. 



the modifications of it in different plants are more 

 numerous than among animals. The illustration 

 of these varieties must be deferred, till we come 

 to consider the structure of the bark, of which 

 the epidermis is usually considered a layer. 



Such are the principal solid components of the 

 vegetable body. Other solid matters certainly 

 enter into the structure of some plants ; but, as 

 those are not common to the vegetable race, they 

 cannot be classed amongst the general compo- 

 nents. Perhaps, also, all the parts which have 

 been examined may be resolved into modifications 

 of the membranous and cellular textures, which 

 might consequently be regarded as the only real 

 solid vegetable components ; but, although we 

 allow that the vessels, ligneous fibre, glands, and 

 epidermis most probably are composed of mem- 

 branous, or cellular texture, differently modified, 

 yet, as each of these parts possesses very distinct 

 functions, such a refinement would only throw 

 obstacles in our way towards the attainment of 

 truth; I have, therefore, considered it preferable 

 to regard them as distinct components. 



