TWINERS AND CLIMBERS. 217 



inwards and outwards is just the process which 

 would be mechanically adopted to secure a rose to a 

 trellis-work. 



Of root-climbers our most familiar indigenous 

 illustration is the ivy (Hedera helix), which ascends 

 by means of rootlets, which adhere to the wall or old 

 trunks, and thus enable the plant to reach the summit 

 of its ambition. Dr. Spruce, alluding to a South 

 American plant (Marcgravia umbellata) which grows 

 against the trunks of trees by means of claspers or 

 roots, remarks, that when it has reached the light and 

 the branches become free, the stems which before 

 were flattened become rounded, and the leaves are 

 altered in character and general appearance. To a 

 certain extent this is also true of the ivy, for when it 

 has reached the top of an old trunk and the free 

 branches are produced, they are destitute of rootlets, 

 and the leaves are smaller, more narrowed towards 

 the footstalk and otherwise modified. 



There is also a species of fig (Ficus repens) which 

 climbs a wall in the same manner as the ivy. The 

 rootlets of this plant, when pressed lightly on slips 

 of glass, were found to emit minute drops of a clear 

 fluid, which is slightly viscid. This fluid exhibited 

 the remarkable faculty of remaining fluid during 1 38 

 days. Other rootlets, left in contact with glass for a 

 longer period, secreted larger drops of fluid, which 

 were more tenacious, and could be drawn out in 

 threads. Other rootlets, left for a still longer period 



