CHAPTER III. 



Tendril-Beakers. 



Nature of tendrils Bigxoniace^:, various species of, and their different 

 modes of climbing Tendrils which avoid the light and creep 

 into crevices Development of adhesive discs Excellent adapta- 

 tions for seizing different kinds of supports Polemoxiace^e 

 Cobxa scandens, much branched and hooked tendrils, their manner 

 of action Legitminos^: Composite Smilace^e Smilax asjyera, 

 its inefficient tendrils Fumariaceje Corydalis claviculata, its 

 state intermediate between that of a leaf-climber and a tendril- 

 bearer. 



By tendrils I mean filamentary" organs, sensitive to 

 contact and nsed exclusively for climbing. By this 

 definition, spines, hooks and rootlets, all of which are 

 used for climbing, are excluded. True tendrils are 

 formed by the modification of leaves with their petioles, 

 of flower-peduncles, branches,* and perhaps stipules. 



* Never having had the oppor- 

 tunity of examining tendrils 

 produced by the modification of 

 branches, I spoke doubtfully about 

 them in this essay when ori- 

 ginally published. But since 

 then Fritz Midler has described 

 (Journal of Linn. Soc. vol. is. p. 

 344) many striking cases in South 

 Brazil. In speaking of plants 

 which climb by the aid of their 

 branches, more or less modified, 

 he states that the following stages 

 of development can be traced : 



(1.) Plants supporting themselves 

 simply by their branches stretched 

 out at right angles for example, 

 Chiococca. (2 ) Plants clasping a 

 support with their unmodified 

 branches, as with Securidaca. 

 (3.) Plants climbing by the ex- 

 tremities of their branches which 

 appear like tendrils, as is the case 

 according to Endlicher with 

 Uelinus. (4.) Tlants with the r 

 branches much modified and 

 temporarily converted into ten- 

 drils, but which may be again 



