Chap. III. BIGNONIACE^. 99 



these branched tendrils the course of the stream of 

 light which entered the box. I left these tendrils 

 undisturbed for above 24 hrs., and then turned the 

 pot half round ; but they had now lost their power of 

 movement, and could not any longer avoid the light. 



When a tendril has not succeeded in clasping a 

 support, either through its own revolving movement or 

 that of the shoot, or by turning towards any object 

 which intercepts the light, it bends vertically down- 

 wards and then towards its own stem, which it seizes 

 together with the supporting stick, if there be one. 

 A little aid is thus given in keeping the stem secure. 

 If the tendril seizes nothing, it does not contract 

 spirally, but soon withers away and drops off. If it 

 seizes an object, all the branches contract spirally. 



I have stated that after a tendril has come into 

 contact with a stick, it bends round it in about half 

 an hour ; but I repeatedly observed, as in the case 

 of B. speciosa and its allies, that it often again loosed 

 the stick ; sometimes seizing and loosing the same stick 

 three or four times. Knowing that the tendrils avoided 

 the light, I gave them a glass tube blackened within, 

 and a well-blackened zinc plate : the branches curled 

 round the tube and abruptly bent themselves round 

 the edges of the zinc plate; but they soon recoiled 

 from these objects with what I can only call disgust, 

 and straightened themselves. I then placed a post 

 with extremely rugged bark close to a pair of tendrils ; 

 twice they touched it for an hour or two, and twice 

 they withdrew ; at last one of the hooked extremities 



