MODIFICATION OF THE ORGANS OF PLANTS 77 



and toothed at the edges. During germination the 

 seed-leaves remain within the seed as with Lathyrus 

 Aphaca. 



The first leaf is upright and reed-like in shape 

 (fig. 42, A 1). Its principal function is to pierce 

 the layer of soil which 

 covers the grain, thus 

 allowing the little ter- 

 minal bud to emerge 

 into the light. Com- 

 pared with the other 

 leaves, this needle-like 

 leaf seems to have con- 

 siderably degenerated. 

 The plant next pro- 

 duces a series of little 

 slender short-stemmed 

 leaves which grow 

 under the water. The 

 first of these leaves 

 are narrow and ribbon- 

 like (fig. 42, A 2); the 

 next are broader (fig. 

 42, B), then follow 

 more slender sub- 

 merged leaves, but with no lateral barbs (fig. 42, c) ; 

 then floating leaves, the edges of which are not 

 dentated, and last of all there are some leaves with 

 dentated edges. Owing to their submergence, the 

 basilar leaves of Nymphaea have greatly degener- 



Fig. W.Nymphcca dentata. 

 A, seedling with two leaves (1, 2) ; B, C, 

 leaves taken from older plants. 



