144 



PHYSIOLOGICAL BOTANY. 



cells. In the early stages of the plant's life, the Proto- 

 plasm is a naked mass, but it very soon surrounds 

 itself with a wall, as in Figs. 465 A 



and 466. Inside the cell-wall it 

 arranges itself into a great variety 

 of forms. 



In Fig. 467, A shows new cells, 

 with the protoplasm evenly distrib- 

 uted, and nuclei forming, k. Fig. 

 467, B, great changes have taken 

 place, cell-sap has been introduced, 

 and the protoplasm is much vacuo- 

 lated, and appears either floating 

 freely in the cell-sap, spread along the 

 cell-wall, or otherwise aggregated. 

 In Fig. 468, A, the protoplasm seems 

 to be aggregating, and spots or vac- 

 uoles are appearing in its midst. 

 Fig. 468, B, the protoplasm is form- 

 ing in globular masses around por- 

 tions of sap. These little vesicles 

 are frequently furnished with the 

 green coloring matter of the plant. 

 Fig. 468, (7, highly magnified cell, 

 in^which the protoplasm has re- 

 treated from the cell-wall under 



467 



. .. ii j 4 ^7, -^' ^ ery y un s cells from 



the aCtlOn OI Weak SUlphUriC add nearthetipoftherootofFritilla- 



ria ; B, cells from a part a little 



and iodine. higher up in the root; s, a, s, sap; 



Jc, x, y, nuclei and nucleoli form- 



369. Protoplasm is complex and mg; ?, protoplasm, 

 constantly changing in its constitution. It yields to 

 chemical analysis materials similar to egg albumen, 

 and is the living substance of the cell; its appearan< 

 under the microscope is shown in Figs. 465-468, 



