110 



HOW PLANTS CLIMB 



finds a support, the coiling would tend to twist it in two 

 It will be found, however, that the tendril coils in differ- 

 ent directions in different parts of its length. In Fig. 

 163 the change of direction in the coil occurs at the 

 straight place near the middle. In long tendrils of cucum- 

 bers and melons there may be several changes of direction. 

 227. Tendrils may be either branches or leaves. In 



164. The fruit-cluster and tendril of grape are homologous. 



the Virginia creeper and grape they are branches; they 

 stand opposite the leaves in the position of fruit -clusters 

 (Fig. 164), and sometimes one branch of a fruit -cluster 

 is a tendril. These tendrils are therefore homologous 

 with fruit -clusters, and fruit -clusters are branches. 



228. In some plants tendrils are leaflets. Examples 

 are the sweet pea (Fig. 165) and common garden pea. 

 In Fig. 165, observe the leaf with its two stipules, petiole, 



