MINUTE ANATOMY OF FLOWERING PLANTS 213 



3oU. Sectional \\&\v of young cella from 

 the root tip. 



metit, absoi-ptioii of food fnatcrial, assimilation — these 

 acti\'ities are cai-rietl 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 migiit select cells from the apex 

 of a growing stem or root, 

 or from a leaf rndiment, or 

 from the young, growing- 

 fruit. Thin sections cut 

 from any of these regions 

 would show, under the com- 

 pound micro- 

 scope, the 

 cells as sev- 

 eral angled, 



thin - walled components of the tissue 

 (Fig. 350). 



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- 

 cj'ties of protoplasm is afforded by the raw 

 white of egg. The fluidity varies in differ- 

 ent portions of the protoijlasmic body of the 

 cell, some parts being relatively tirm, oth- 

 ers containing a very large percentage of 

 water, and being, therefore, capable of 

 .,.,., I . more or less vapid movement in circulating 



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

 tlrmi^uai '^^^^^^ '^^ Suspended near the center l.)y 

 cell the cir- thi'eads of protoplasm (Fig. 360), the cur- 



CLilation of . -, ■ ,n "",1 i 



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

 is indicated toward and away from the nucleus. Two 



by arrows. .. . r^ i i i • 



opposite currents may often be ol;)serveil m 

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

 362 the whole body of protoplasm, except that part 



