62 LEAF-CLIMBERS. Chap. II. 



These filaments or rudimentary leaves, as well as 

 the petioles of the perfect leaves, whilst young, are 

 highly sensitive on all sides to a touch. The slightest 

 rub caused them to curve towards the rubbed side in 

 about three minutes, and one bent itself into a ring 

 in six minutes ; they subsequently became straight. 

 When, however, they have once completely clasped a 

 stick, if this is removed, they do not straighten them- 

 selves. The most remarkable fact, and one which I have 

 observed in no other species of the genus, is that the 

 filaments and the petioles of the young leaves, if they 

 catch no object, after standing for some days in their 

 original position, spontaneously and slowly oscillate a 

 little from side to side, and then move towards the 

 stem and clasp it. They likewise often become, after 

 a time, in some degree spirally contracted. They 

 therefore fully deserve to be called tendrils, as they 

 are used for climbing, are sensitive to a touch, move 

 spontaneously, and ultimately contract into a spire, 

 though an imperfect one. The present species would 

 have been classed amongst the tendril-bearers, had not 

 these characters been confined to early youth. During 

 maturity it is a true leaf-climber. 



Trojyseolum azureum. An upper internode made four 

 revolutions, following the sun, at an average rate of 

 1 hr. 47 m. The stem twined spirally round a 

 support in the same irregular manner as that of the 

 last species. Rudimentary leaves or filaments do not 

 exist. The petioles of the young leaves are very 

 sensitive : a single light rub with a twig caused one 



