LECT. III.] GENERAL SOLID COMPONENTS. 69 



LECTURE III. 



GENERAL COMPONENTS OF THE VEGETABLE 

 STRUCTURE. 



IP any number of plants of the most diversified 

 forms and structure, be individually cut,, or divided 

 or torn asunder, each and all of them will be found 

 to consist of solid and fluid materials. A plant 

 may therefore, as far as structure is concerned, be 

 represented as a congeries of solids and fluids. 

 Whilst, however, regarding* it in this point of view, 

 we must always bear in mind that both constituents 

 are under the influence of the living principle; 

 that the fluid parts, often differing widely in 

 chemical properties, are not only retained within 

 certain channels, and kept from mixing with 

 each other ; b 4 ut are moved progressively by a 

 specific action of the solids through the whole body 

 of the plant ; and altered in their characters so com- 

 pletely, that the secretions which result have no 

 affinity whatever to the fluids imbibed from the soil 

 and the atmosphere from which they are formed ; 

 and that, as in the living animal body, waste and 

 repair are constantly going on in the vegetable 

 system. 



