CHAPTER VI 



FOOD RESERVOIRS 



74. STOREHOUSES. — All greathj thickened or congested 

 parts are reservoirs for the storage of plant-food. This 

 food is mostly starch. Potatoes, beets, turnips, thick 

 rhizomes, seeds, are examples. Recall how potatoes sprout 



42. Potato spi-uuls 



Tlie sprouts have used tlie food stored in the tuber, 

 and the tuber has shrivelled. 



in the cellar (Fig. 42) : the sprouts are produced from the 

 stored food. 



75. The presence of starch can he determined by apply- 

 ing diluted tincture of iodine to the part: if a blue or 



(31) 



