1891.] D. Prain — The Vegetation of tlie Coco Group. 34? 



Among these erect vascular plants the proportion of woody to her- 

 baceous is therefore : — 



Woody sp. : Herbaceous sp. : : 3 : 2. 



Of the climbers 35 are woody and 43 are herbaceous so that here 

 the proportion is : — 



Woody sp. : Herbaceous sp. : : 2 : 2|. 



Instead therefore of being lower amongst climbers than erect species, 

 the proportion of herbaceous species to woody ones, when attention is 

 confined to vascular plants only, is actually higher. And in number 

 of individuals too there is a much moi-e even balance among climbing 

 species, since herbaceous climbing species, as well as woody ones, can 

 easily raise themselves to the light and air for want of which no great 

 quantity of herbaceous undergrowth can exist ; indeed the herbaceous 

 climbing species possess many advantages over their woody rivals, for 

 they are not as a rule so heavy and as, moreover, they sometimes (e. g., 

 Modecca, Trichosanthes, Dioscorea, Gloriosa) die down annually, they do 

 not destroy the species on which they are supported so soon as do heavy 

 perennial creepers like Galamios, Thunhergia, Anodendron, Ghonemorpha, 

 Derris, etc., which in a few season . drag down the trees on which they 

 climb. 



Some of the woody climbers, such as Anodendron and Thunhergia, 

 climb to great heights, and are not surpassed in this i-espect even by the 

 Modecca. The majority of the woody climbers, however, like Sarcostigma, 

 Salacia, Pisonia aculeata, Pleeospermum, the species of Acacia and of 

 Gapparis, are not to be found on tall trees at all, but load heavily the 

 woody undergrowth of small trees and shrubs that forms the bulk of the 

 forest. Nor is it unusual to find the forest, where composed of tall trees, 

 exhibiting both classes of creepers ; the characteristic lofty creepers on 

 the tall trees overhead, the heavy woody creepers on the shrubby under- 

 growth below. 



Of the climbing species 20, or 25%, are armed. As a rule the 

 armed species may be said to belong to the class of undergrowth clim- 

 bers ; with the exception of the two species of Galamus, the lofty climbers 

 are unarmed. 



The habit of the Coco Island species is shewn in the subjoined table. 



46 



