go 



PLANTS 



to the support by the contracting spirals. Tendrils in some 

 instances end in adhesive discs by which the plant is enabled to 

 cling to a smooth plane surface. Lastly, the twining climbers, 

 swaying their growing tips in a spiral around the axis of support, 

 coil themselves bodily about their host. In neither of these 

 cases does the climber obtain any nourishment from the host, 



Fig. 44. — The trumpet vine, a climber. 



although the latter may be seriously handicapped or even 

 finally destroyed through shading by its vigorous yet dependent 

 hanger-on. 



213. Epiphytes constitute another class of plants which 

 depend upon others for mechanical support. They have no 



