110 TENDRIL-BEARERS. Cuap. IIT. 
The perfect manner in which the branches arranged 
themselves, creeping like rootlets over every inequality 
of the surface and into any deep crevice, is a pretty 
sight; for it is perhaps more effectually performed 
by this than by any other species. The action is 
certainly more conspicuous, as the upper surfaces of 
the main stem, as well as of every branch to the 
extreme hooks, are angular and green, whilst the lower 
surfaces are rounded and purple. I was led to infer, 
as in former cases, that a less amount of ight guided 
these movements of the branches of the tendrils. 
I made many trials with black and white cards and 
glass tubes to prove it, but failed from various causes ; 
yet these trials countenanced the belief. As a tendril 
consists of a leaf split into numerous segments, there is 
nothing surprising in all the segments turning their 
upper surfaces towards the light, as soon as the tendril 
is caught and the revolving movement is arrested. 
But this will not account for the whole movement, for 
the segments actually bend or curve to the dark side 
besides turning round on their axes so that their upper 
surfaces may face the light. 
When the Cobxa grows in the open air, the wind 
must aid the extremely flexible tendrils in seizing a 
support, for I found that a mere breath sufficed to cause 
the extreme branches to catch hold by their hooks of 
twigs, which they could not have reached by the 
revolving movement. It might have been thought 
that a tendril, thus hooked by the extremity ofa single 
branch, could not have fairly grasped its support. 
