TUBERS— STARCH 95 



lem artichoke, the tubers of which have buds ar- 

 ranged two by two on opposite swellings, from front 

 to back and from right to left in turn, exactly as are 

 leaves and buds on the stem. 



"The potato feeds its buds on a farinaceous sub- 

 stance called fecula or, in less learned language, 

 starch. It is the very material that makes the vege- 

 table so rich in nutriment for us. We turn to our 

 own account what tbe plant has stored 

 up for its young shoots. Starch is con- 

 tained in the extremely small cavities 

 with which the flesh of the tuber is all 

 riddled. These cavities are called cells. 

 They are microscopic sacs made of a 

 iine membrane and having no opening. rh ( o , 

 Crammed full of starch grains and Pot8to 

 crowded one against another, they compose the 

 fleshy substance of the potato. But these cavities 

 are so small that a person would strain his eyes in 

 vain in any attempt to see them in the cross-section 

 of a potato. A magnifying glass is necessary. So 

 minute are the cells that in a piece of potato no larger 

 than a pin's head there *is room for dozens and doz- 

 ens of them. This picture -shows you, but much 

 larger than in nature, a potato cell with the grains 

 of starch it encloses." 



"How beautifully," exclaimed Emile, "those 

 grains of starch are arranged in their little cubby- 

 hole ! They might be taken for a nest of eggs. And 

 you say there are heaps and heaps of these little 

 starch cells?" 



