Rubber 



295 



and flows readily. It coagulates on exposure to the air, and is sometimes smoked over a fire 

 of palm nuts, as described in the case of Para rubber. 



In Ceylon, where the tree was planted formerly on a fairly extensive scale, the. yields of 

 rubber were low, and little attention is given to this plant now. The greatest export from 

 Ceylon was about 17,500 lb. in 1895, but two years later it had decreased to less than 3,000 lb. 

 Large plantations, however, exist in Brazil, whence there is a. considerable export. 



The Brazilian product is exported as (1) pale yellowish brown threads, (2) small flat cakes, 

 and (3) smoked rubber prepared like Para rubber. 



Ceara rubber is of good quality, although not so valuable as Para rubber. 



LANDOLPHIA RUBBERS 



The plants producing this group of rubbers are chiefly large woody climbers which 

 in the forests of the warmer parts of Africa, often reaching to the tops of high trees and for 

 dense, tangled masses of more or less rope- 

 like stems. Many of them bear in profusion 

 conspicuous jasmine-like flowers, often sweetly 

 scented, and succeeded by large, frequently 

 brightly coloured, and sometimes edible, fruits. 

 They belong to the genus Landolphia of the 

 natural order Apocynaceae. In Great Britain 

 this order is represented by the pretty " Peri- 

 winkles " (Vinca major and V. minor), whose 

 stems also yield a milky juice or latex, although 

 not rich in rubber as is that of their African 

 relatives. Owing to their habit of growth, the 

 Landolphias are not very well suited to culti- 

 vation, although efforts made in this direction 

 have met with some success. 



There are many species of Landolphia, but 

 they do not all yield good rubber, and we may 

 restrict our attention to the more important. 



The West Coast Species. In Senegal, 

 Gambia, and Sierra Leone, that is, generally 

 speaking, in the more northerly portion of 

 West Africa, Landolphia Heudelotii is a most 

 important source of rubber. 



As we proceed farther south this species is 

 replaced by Landolphia owariensis, which is 

 widely distributed on this side of the continent, 

 ranging from about Sierra Leone right down 

 to Angola. It is one of the principal rubber 

 plants of French West Africa, the Gold Coast, 

 Nigeria, the Congo, and Portuguese West Africa. 

 In the Congo there also occurs Landolphia Foreti 

 and other species. Another interesting form is 

 L. Henriquesiana, a small shrubby plant spring- 

 ing from underground stems or rhizomes which, 

 when pounded, form one of the sources of 

 " root rubber." 



The East Coast Species. The principal By permission ot Messrs. MacUmn & Co., Shoe Lane 



rubber plant on this side of Africa is Landolphia « half herring-bone " system 



grow 

 ming 



