TWINERS AND CLIMBERS. 187 



they form tangled festoons, and, covered themselves 

 with smaller creepers and parasitic plants, hide the 

 parent stem from sight."^ 



In this temperate clime of ours we know nothing 

 of the gigantic climbers of the tropical forests, but 

 we have many plants with a similar habit, on a small 

 scale, quite sufficient to give us an interest in the 

 phenomena concerned in the twining process. It 

 was in 1865 that Mr. Darwin's memoir of the habits 

 of climbing plants first made its appearance," and, as 

 since revised, is now the text-book on the subject. 



In this work scandcnt plants are divided into four 

 classes, applicable alike to our purpose: — (i) Twiners, 

 those which twine spirally round a support unaided 

 by any other movement ; (2) Climbers, endowed with 

 irritable organs, which, when they touch any object, 

 clasp it ; (3) Scramblers, which ascend merely by the 

 aid of hooks ; and (4) Root-climbers, which ascend 

 by means of rootlets attached to their support. Of 

 these four classes the first and second are of most 

 importance, being by far the most numerous, and 

 true climbers ; the third and fourth being pseudo- 

 climbers. 



We could not desire a more familiar or better 

 illustration of a " twiner " than the hop {Humulus 



^ " Travels on the Amazon," by A. R. Wallace, p. 

 - " Journal of the Linnsean Society," vol. i.x.. p. i. 



