MINUTE ANATOMY OF FLOWERING PLANTS 213 



ment, absorption of food material, assimilation — these 

 activities are carried on by the cooperation of the cells 

 composing the plant. This being the case, it is important 

 to know something of the structure of the typical vege- 

 table cell. 



495. Structure of the cell. — In illustration of the 

 typical vegetable cell, we might select cells from the apex 

 of a growing stem or root, 

 or from a leaf rudiment, or 

 from the young, growing 

 fruit. Thin sections cut 

 from any of these regions 

 would show, under the com- 

 pound micro- 



scope, 



the 



CeiiS as Sev- 359. Sectioual view of young ceils from 



eral angled, the root tip. 



thin - walled components of the tissue 



(Fig. 359). 



496. The living substance of the cell is 

 protoplasm. It lias been described as being 

 of a jellylike consistency. A better illus- 

 tration of the semifluid, yet cohesive, prop- 

 erties of protoplasm is afforded by the raw 

 w^hite of egg. The fluidity varies in differ- 

 ent portions of the protoplasmic body of the 

 cell, some parts being relatively firm, oth- 

 ers containing a very large percentage of 

 water, and being, therefore, capable of 

 more or less rapid movement in circulating 

 of a Nettle, currents. In some cells in which the nu- 

 t^ermi^nai cleus is suspended near the center by 

 cell the cir- threads of protoplasm (Fig. 360), the cur- 



culation of , -, • j 1 j_i 1 



protoplasm I'^i^ts may be seen m the threads, passing 



is indicated toward and away from the nucleus. Two 



opposite currents may often be observed in 



the same thread. In cells like the largest one of Fig. 



362 the whole body of protoplasm, except that part 



3G0. Stingin.L: hair 



