VII. 1 



LEA VES. 



8i 



13. Foliage-leaves are sometimes curiously modified, 

 either to serve some special purpose, or by the absence 

 of the blade, or the reduction of the leaf to a mere spine. 

 Thus in the Pea we find the extremity of the common 

 petiole and two or more of the lateral leaflets assume the 

 form of tendrils^ enabling the weak stem to lay hold of 



Fig. 53. Pinnate (quadrifoliolate) leaf, with stipules. ^7z/>. stipules 



supports in climbing. Compare with the tendrils of the 

 Pea those of the Grape-vine, which we have described as 

 branches modified for the same purpose (p. 72), 



In Barberry and its allies, common in the Himalayas, the 

 first leaves borne by the branches are reduced to sharp 



G 



