72 CELLULAR TEXTURE. [_LECT. III. 



in some stages of the formation of the cellular 

 texture, yet it is incorrect, as far as regards its 

 fully organized state. Mirbel, who examined them 

 with more attention, first pointed out their real 

 nature. He discovered that they are similar to 

 the geometrical cells of a honeycomb, although 

 sometimes of a longitudinal figure, and that 

 the divisions of the membrane which forms 

 them are common to contiguous 

 cells (fig. a) ; that they communi- 

 cate with each other by means 

 of pores and slits, about the three 

 hundredth part of a line in diame- 

 ter (fig. b)*; and that through these 

 perforations the vegetable juices 

 they contain are slowly transfused. 

 The same author asserts also, that 

 these pores are surrounded with 

 borders, " petits bourrelets epais et 

 calleux ;" but this is doubtful. He 

 describes the perforations as being few and scattered 

 in the true hexagonal cells; but numerous and 

 arranged transversely in regular series, in the 

 longitudinal -f~. The membrane itself is so thin, 

 that, when examined through a microscope, with 



* It must be recollected that, in these representations and 

 in all those of the vegetable internal structure which are to 

 follow, the parts are very highly magnified. 



t Element de Phys. veget. Parlie l m , p. 29. 



