30 GENERAL TEXTURE OF l^LAN TS. 



for their hexagonal figure.* See Tab. I. f. a. The 

 membranous sides of all these cells and tubes are very 

 thin, more or less transparent, often porous, variously 

 perforated or torn. Of 'he tubes, some are without any 

 lateral perforations, f. b, at least for a considerable ex- 

 tent ; others pierced with holes ranged in a close spiral 

 line, f.c; in others several of these holes run together, 

 as it were, into interrupted spiral clefts, f.d; and in 

 some those clefts are continued, so that the whole tube, 

 more or less, is cut into a spiral line, f.e; which, in 

 some young branches and tender leaves, will unroll to a 

 great extent, when they are gently torn asunder. The 

 cellular texture especially is extended to every part of 

 the vegetable body, even into the thin skin, called the 

 cuticle, which covers every external part, and into the 

 fine hairs or down which, in some instances, clothe the 

 cuticle itself. 



Before we offer any thing upon the supposed func- 

 tions of these different organs, we shall take a general 

 view of the Vegetable body, beginning at the external 

 part and proceeding inwards. 



* In microscopic figures they are generally drawn like circles 

 intersecting each other. 



