194 



that's it ; 



and mushrooms, are said to be 

 wholly composed of it. 



4 f~~i=zt 



H 



543. 



The nature of the cells that 

 abound in vegetable structures 

 may be comprehended by exa- 

 mining those of the orange, 3, 

 3 forming the 



bead- like 

 strings that 

 constitute 

 the juicy 

 parts. Each 

 of these 

 cells has an 

 internal ar- 

 544. rangement 

 exceedingly delicate, and per- 

 haps scarcely less complicated 

 than that of the orange itself. 



In juicy and succulent vegetable 

 substances the cells are larger and 

 4 more easily 



observed 

 than in the 

 more solid 

 structures. 

 The cells of 

 the straw- 

 berr y, 4, 

 are of large 

 545 - size, and 



contain a slightly coloured fluid, 

 enclosing a rounded nucleus. 



These are thin -walled cells, and 

 differ material lv from others that 



are thick-walled. When eating a 

 pear, we find the outer parts soft 

 and juicy, but near the core we 

 observe a gritty substance; this 

 consists of thick-walled cells, which 

 are there plentifully interspersed 

 with the softer cellular tissue. 

 The arrangement of these cells 

 presents, in many substances, a 

 beautiful appearance when exa- 

 mined by the microscope, as in 

 the seed of the star anise, 6.* 

 The cells are indicated by the 

 irregularly circular lines, 7 ; the 



dark spots, 8, represent the cen- 

 tres, or cavities of the cells ; the 

 dark lines, 9, are the radii, 

 or nutritive vessels, 10 

 which run through 

 the walls of each 

 cell. 



The vessels, 2, are ||P 

 tubes through which 

 the vegetable fluids 

 circulate, and, like 

 the cells, their for- 

 mation and arrange- 

 ment present great 

 variety. Spiral ves- 

 sels, 10, are cylin- 

 drical tubes, having 

 conical extremities, 1 1 , 



647. 



* TUicium atii»atum 



