MODIFICATION OF THE ORGANS OF PLANTS 79 



which are thread-like and sensitive to contact, are 



FIG. 43. Cobaea scandens. 



A, B, seedlings ; the leaves of the second end in tendrils ; C, young leaf of 

 udult plant. 



modifications of either stems, leaves, or roots, the 

 latter being the most rare. 

 We will confine our atten- 

 tion at present to those 

 adapted from leaves. 



In Cobaea scandens the 

 first two leaves of the 

 seedling usually terminate 

 in a leaflet (fig. 43, A); 

 the leaves which come 

 after are much finer and 

 are modified into tendrils 

 (fig. 43, c). 



This modification of 



leaflets into tendrils, Which FlG . 44 ._Basal portion of a young 



entails the almost com- ***"***** 



plete disappearance of the original assimilative func- 



