GENERAL TEXTURE OF PLANTS. 1 1 



mals. The anatomical observations of Mirbel go further 

 than those of Grew, &c., and it is necessary to give 

 a short account of his discoveries. 



He finds, by the help of the highest magnifying 

 powers, that the vegetable body is a continued mass of 

 tubes and cells; the former extended indefinitely, the 

 latter frequently and regularly interrupted by transverse 

 partitions. These partitions being ranged alternately 

 in the corresponding cells, and each cell increasing 

 somewhat in diameter after its first formation, except 

 where restrained by the transverse partitions, seems to 

 account for their hexagonal figure*. See Tab. I.jf. a. 

 The membranous sides of all these cells and tubes are 

 very thin, more of less transparent, often porous, va- 

 riously perforated or torn. Of the tubes, some are 

 without any lateral perforations,/./;, at least for a con- 

 siderable extent ; others pierced with holes ranged in a 

 close spiral line,/, 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, 

 J\ 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 



* In microscopic figures they are generally drawn like circles inter- 

 secting each other. 



