a 
ment which results in spiral coils, since 
the tendril is fastened at both ends (Fig. 
48). This curving and twist- 
ing of the tendril between its 
fastened extremities naturally 
results in two spiral coils run- 
ning in opposite directions. In 
this way the stem is fastened 
to its support by numerous 
spiral springs. All of these 
movements and their results 
may be observed by cultiva- 
ting a plant such as the star- 
cucumber, which grows rapidly 
and has conspicuous and very 
sensitive tendrils. In the case 
of the ordinary climbing wood- 
bine and certain species of ivy, 
which cling to walls or tree 
Fie. 49.—Woodbine ina 
eciduous forest. 
Fic. 50.—W oodbine clinging to a wall 
by means of tendril suckers. 
