THE PROBLEM OF SEX IN PLANTS 



347 



entire new plant. A leaf of begonia laid on moist sand 

 will give rise to several new plants wherever it is cut (Fig. 

 254). Leaves of the sundew (Drosera) frequently strike 



Fig. 253. — Regeneration at the leaf-base of potato leaves {Solanum 

 tuberosum), a, roots formed; h, tuber-like enlargement; c, same as h, 

 with roots; d, formation of true tuber. (After Miss Elsie Kupfer.) 



Fig. 254. — Young plantlets developing from the edges of lacerations 

 made in a large leaf of Rex begonia. ' 



root at the tip and develop new plants (Fig. 255), while 

 the leaves of Bryophyllmn normally produce marginal 

 buds from which new plants develop (Fig. 256). As 



