MICROSCOPIC OBJECTS. 



Fig. 9. Stellate Tissue from Rush (Juncus communis), 

 x 90, Endogen. 



This drawing is from a transverse section of the pith from 

 the stem of the Hush, as seen under the parabolic reflector. 

 It illustrates the stellate parenchyma, or cellular tissue. The 

 form of the component cells is generally that of a six-rayed 

 star, the ends of the rays of one cell being in apposition with 

 those of the surrounding cells. The intervals between the 

 cells, or the intercellular spaces, as they are called, in this 

 case, as in most water-loving plants, contain air; and it is 

 this, together with the loosely formed stellate tissue, that 

 tends to make the Rush so light and elastic. When the 

 pith is mounted in liquid or in Canada balsam, the air is 

 displaced, and the whole appears transparent. 



It is best seen when mounted dry, but may be well viewed 

 in liquid. 



Fig. 10. Longitudinal Section of the Willow (Salix alba), 

 showing dotted ducts in situ, x 240, Exogen. 



This section is the same as fig. 66, only much more mag- 

 nified; it illustrates the dotted ducts. Ducts are regarded 

 as a form of vascular tissue terminating in abrupt or blunt 

 ends, by which characteristic they may be distinguished from 

 liber -cells and vessels, which terminate in tapered ends (see 

 figs. 13, 14, & 17; also Wood Sections); when examined 

 under a high power, say ^, they appear much dotted, whence 

 the name. The tissue of which ducts are composed (unlike 

 true vascular tissue) cannot be unrolled. 



It is best examined in the dry state. 



