104 SCRAMBLIXG PLANTS [CH. 



Derris hantamensis, where the adventitious rootlets form 

 spiny outgrowths which aid in climbing. 



What may be termed scrambling plants offer sug- 

 gestive examples of such as are, so to speak, learning to 

 climb. The young shoots of the wild Rose, Bramble and 

 especially the Rattans (the climbing Palm or Calamus) 

 are at first quite independent, but as they push their way 

 through or over the surface of hedges or other thickets, 

 the recurved prickles on their stems, which present no 

 obstacle to forward growth, offer so many points of more 

 or less definite hold-fast on the interlacing branches and 

 twigs against which the shoot leans, that it is impossible 

 for the long stems to fall. This is well demonstrated 

 by trying to pull such a shoot out of a hedge by the cut 

 lower end. In the Rattans the recurved harpoons are in 

 part leaflets. 



Similar hold-fasts are afforded by the much smaller and 

 more numerous asperities on the shoots of the Cleavers 

 {Galium), or by the out-spread or recurved leaves or 

 branches, thorns, &c. of numerous other thicket and 

 hedge-plants, such as species of Geranium, Asparagus, 

 Barberries, Lycium, &c. which weave themselves through 

 the tangled masses of twigs or scramble over them in 

 various ways. 



Still more efficient are the recurved persistent petioles 

 of certain Combretacese, Jasmineae, &c,, which remain as 

 hooks after the leaf has fallen. Certain Bamboos are 

 held up by their long, hard reflexed buds. 



Id twining plants we find more special adaptations to 

 the habit of using other plants or parts of plants as a 

 support. 



As in previous cases the young shoots emerge from 

 the soil as erect and self-supporting structures, but the 

 terminal portion, of two or more young internodes and 



