LEAF-CLIMUEKS. 45 



Corydalis claviculata. — This plant is interesting from being in 

 a condition so exactly intermediate between a leaf-climber and a 

 tendril-bearer that it might have been described under either 

 head ; but, for reasons hereafter assigned, it is classed amongst 

 tendril-bearers. 



Besides the plants already described, Bignonia unguis and its 

 close allies, though aided by tendrils, as will hereafter be de- 

 scribed, have clasping petioles. According to Mohl (S. 40), 

 Cocculus Japonicus (one of the Menispermaeea>) and a fern, the 

 Ojjhioglossum Japonicum (S. 39), climb by their leaf-stalks. 



"We now come to a small section of plants which climb by the 

 aid of the produced midribs or tips of their leaves. 



G-lokiosa. — G. Plant ii (Liliaeese). — The stem of a half- 

 grown plant continually moved, generally describing an irregular 

 spire, but sometimes ovals, with the longer axes running in differ- 

 ent directions. It cither followed the sun, or moved in an oppo- 

 site course, and sometimes stood still before reversing its course. 

 One oval was completed in 3h. 40 m.; of two horseshoe-shaped 

 figures, one was completed in 4 h. 35 m. and the other in 3 h. The 

 tip of the shoot, in its movements, reached points between four and 

 five inches asunder. The young leaves, when first developed, 

 stand up nearly vertically ; but by the growth of the axis, and by 

 the spontaneous bending down of the terminal half of the leaf, 

 they soon become much inclined, and ultimately horizontal. The 

 end of the leaf forms a narrow, ribbon-like, thickened projection, 

 which at first is nearly straight ; but by the time the leaf has got 

 into an inclined position, the end has bent itself downwards into 

 a well-formed hook ; and this is now strong and rigid enough to 

 catch any object, and, when caught, to anchor the plant and stop 

 the revolving movement. This hook is sensitive on its inner sur- 

 face, but not in nearly so high a degree as with the many before- 

 described petioles ; for a loop of string, weighing 1-64 grain, pro- 

 duced no effect. When the hook has caught a thin twig or even 

 a rigid fibre, the point may be perceived in from In. to 3h. to have 

 curled a little inwards ; and, under favourable circumstances, in 

 from 8 h. to 10 h. it finally curls round and seizes the object, which 

 it never again looses. The hook when first formed, before the leaf 

 has become inclined, is less sensitive. The hook, if it catches hold of 

 nothing, remains for a long period open and sensitive ; ultimately 

 the tip spontaneously and slowly curls inwards, and makes a 

 button-like, flat, spiral coil at the end of the leaf. One leaf was 



