346 



MALE FERN. 



but with a thin protoplasmic lining; and "conjunctive" 

 parenchyma, the latter mingled with the sieve-tubes and 

 having thin walls and dense protoplasmic contents. The 

 xylem consists of (i) vessels, varying in width, with thick 

 lignified walls; and (ii) "conjunctive" parenchyma like 

 that of the phloem. 



485. L. S. of Pern Stem (Fig. 85). Cut longitudi- 

 nal sections of the stem (or leaf-stalk) ; treat them in 



Fig. 85. FERN. 



Patt of a Longitudinal Section of Stem, passing 

 through a Vascular Strand. 



the same way as the transverse sections, and note the 

 following tissues (compare with the transverse sections 

 and the slides of macerated tissues) : 



(1) The epidermis. 



(2) The parenchymatous ground tissue. 



(3) The phloem, consisting of sieve-tubes with pointed 

 ends and with sieve-areas (perforated by small pores) on 

 the lateral walls; the areas being of irregular outline 

 and separated by thicker portions of cell-wall. These 

 thickened parts give the walls a beaded appearance as seen 

 in longitudinal sections. 



