228 



HUTCHINSON'S POPULAR BOTANY 



283. PtiyUanttms angustifol 

 A leaf-like branch, bearing flowers. 



FIG. 284. Genista 



sagittalis, 



Showing two-edged 



membranous branch 



and twigs. 



" whether we allow light, 

 warmth, or humidity to 

 operate on this side or 

 that ; the particular species 

 always twists in the same 

 direction, the Hop towards 

 the right, the Convolvulus 

 [and Dodder] towards the 

 left. More than this, even 

 if the twining portion is 

 continuously bound in an 

 opposite direction, the re- 

 sult is all the same ; the 

 plant cannot be coerced 



into any other path, and will not depart from the direc- 

 tion peculiar to it. It continues to twist and twine 

 according to an innate tendency inherited from generation 

 to generation, and we can only refer the different directions 

 of twisting to internal causes, to the peculiar constitution 

 of the living protoplasm in each particular plant." It has 

 been asserted by Darwin that the Bittersweet (Solanum 

 dulcamara), a trailer rather than a twiner, is both a left- 

 handed and a right-handed climber when growing near 

 slender stems. Kerner, however, affirms that in many species 

 of climbing plants whose stems, like that of the Bittersweet, 

 increase in thickness from year to year, " the twining is 

 not very conspicuous," and adds of the plant in question 

 that it forms a kind of link " between plants with twining 

 and those with interweaving stems." 



Travellers tell us that we must go abroad in order to 

 obtain just ideas of the habits and eccentricities of climbing 

 and twining plants ; and the accounts which they bring 

 us from the far-off forests of the Amazon and West Indies, 

 from India and the South Pacific Islands, are well calculated 

 to kindle a desire to go thither. They tell us of foot- 

 tangling Mamures,* with creeping stems and fan-shaped 

 leaves, which interlace with wire-like branches of other 

 plants hanging from above. " You look up and around, 

 and then you find that the air is full of wires, that are 

 hung up in a network of fine branches to half a dozen 

 different sorts of young trees, and interwined with as 



* Carludovica, a genus of monocotyledonous plants, most of which 

 are climbing and palm-like, and all of which are tropical. The genus is 

 included in the order Cyclanthaceae. 



