52 LEAF-CLIMBERS. Chap. II, 



with the basal portions of their petioles. The leaves 

 whilst young are nearly of the same shape as those 

 of C. viticella, and act in the same manner like a hook, 

 as will be described under that species. But the leaflets 

 are more divided, and each segment whilst young 

 terminates in a hardish point, which is much curved 

 downwards and inwards ; so that the whole leaf readily 

 catches hold of any neighbouring object. The petioles 

 of the young terminal leaflets are acted on by loops 

 of thread weighing th and even ^th of a grain. 

 The basal portion of the main petiole is much 

 less sensitive, but will clasp a stick against which it 

 presses. 



The leaves, whilst young, are continually and sponta- 

 neously moving slowly. A bell-glass was placed over 

 a shoot secured to a stick, and the movements of the 

 leaves were traced on it during several days. A very 

 irregular line was generally formed ; but one day, in 

 the course of eight hours and three quarters, the 

 figure clearly represented three and a half irregular 

 ellipses, the most perfect one of which was completed 

 in 2hrs. 35 m. The two opposite leaves moved 

 independently of each other. This movement of the 

 leaves would aid that of the internodes in bringing 

 the petioles into contact with surrounding objects. 

 I discovered this movement too late to be enabled to 

 observe it in the other species ; but from analogy I 

 can hardly doubt that the leaves of at least C. viticdla, 

 G. fiammula, and C. vitalba move spontaneously ; and, 

 judging from C. Sieboldi, this probably is the case with 



