CHAPTER VIII. 

 , HOW SOME PLANT PARTS REMAIN RIGID. 



82. Turgidity of plant parts. — In Chapter VI we found that 

 ;he turgescence of a cell depends on the absorption of water by 



Fig. 34. F'g- 35- 



ndian turnip plant just removed from the Same plant half an hour later. It is be- 

 soil. It is rigid. coming limp. 



Drotoplasm. The protoplasm permits the cell-sap to draw the 

 ivater inward by diffusion, but the protoplasmic membrane does 

 lot permit the water to filter out readily, and the outward pressure 



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