= ee 

THE LEAF 45 


Fic. 34. Starch grains 
Upper row, potato and sago ; second row, wheat, rice, and corn; third row, 
bean and Maranta. (x 290) 
sufficient light for photosynthesis will penetrate through a 
thicker layer of tissue than would be the case if the light were 
weak. Fig. 35 shows sections of two leaves from the same plant. 
The one on the right was fully exposed to the sun, while the 
