39 



the most suitable localities, have proved complete failures. The 

 continuous work in one place does not suit the Oriental at all, 

 least of all the Cingalese, Chinese and Malay, the workers of the 

 rubber region in the East. Till the manufacturing classes of 

 Europe can be so acclimatized, as to settle in the hot damp rubber 

 regions, and without deterioration of character and stamina, 

 populate the equatorial belt, it is not at all probable that any 

 large manufactories of vulcanized goods will ever become practi- 

 cable here. 



III. — CASTILLOA RUBBER. 

 A. Cultivation * 



The following information is abstracted from an article by 

 Theodor F. Koschny, San Carlos, Costa Rica, which appeared in 

 the Tropenpflanzer for December 1905. The references to the best 

 variety for cultivation are of particular interest : 



A short time ago only one species of the genus Castilloa, viz., 

 Castilloa elastica, was presumed to yield marketable rubber. In 

 July 1901, the writer distinguished a variety of this species under 

 the suffix alba. The rubber from Castilloa elastica, var. alba, fetches 

 from lod. to Is. more per lb. in Hamburg than that of Castilloa 

 elastica var. mexicana. O. F. Cook has discovered several species 

 of Castilloa on the Pacific side of Central America, all of which 

 yield marketable rubber. H. Pittier has found another species, 

 Castilloa nicogana, near the Gulf of Nicoga. Castilloa costaricana, 

 which grows at high elevations south of 10° N., differs only in the 

 leaves from C. alba ; but it yields a very little rubber of a low 

 quality. Unfortunately, it appears that all the plants sent first to 

 south-east Asia and New Guinea were of this nearly valueless 

 species. It is the one planted first in Java. 



C. elastica, var. mexicana, was the species collected by Dr. Preuss 

 for the German colonies. It produces a good quantity of rubber 

 and its cultivation is remunerative, but the quality of the rubber is 

 inferior to that of C. alba. The latter can replace the best Hevea 

 rubber ; the tree is more cheaply tapped than Hevea ; the prepara- 

 tion of the latex is simpler, and the returns are greater. Dr. C. O. 

 Weber says in regard to his trials of this species: 'The rubber 

 thus obtained is a product of a degree of purity, in which no 

 rubber, not even the finest brands of Para, has ever been offered 

 to the manufacturer.' The scrap rubber, when clean, is valued at 

 the same price as the best Sernamby of Para. 



Castilloa requires a certain amount of shade. It will not grow 

 at all, of course, under the full shade of a forest. With too much 

 shade it forms thin, tall, easily-broken stems which increase but 

 slowly in thickness. But it is not a tree for the open. It grows 

 very well in the open as long as the sap is watery ; but when it is 

 older and taller the sun strikes on the unshaded trunk and warms 

 the thick latex in the bark. This causes the death of many trees 

 even without tapping. Experience has shown, again and again, 



* From "Agricultural News," VI, 125. 



