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The World's Commercial Products 



passes commercially under a great variety 

 of names, mainly denoting the country 

 from which it has been obtained. The 

 tree is also known under different local 

 names ; the Spanish name is Hule or Ule ; 

 the native Aztecs called it Olquaquitl ; 

 other names which have been applied to 

 the plant are Caucho and Tunu. Although 

 we have referred to this rubber as being 

 obtained from one species of plant, there 

 is considerable doubt as to whether this 

 is strictly accurate, and Koschny, who^ 

 has devoted great attention to the tree 

 in Costa Rica, distinguishes and gives 

 separate names to four distinct kinds or 

 varieties, three of which yield rubber 

 whilst the latex of the other forms only a 

 resinous, brittle mass of no value. It is 

 convenient to include all these varieties 

 under the general name of Castilloa 

 elastica, bearing in mind that we may be 

 dealing with several closely related plants, 

 rather than with only one species. 



The Central American rubber tree is 

 found in the forests in its native country, 

 but it does not follow from this that it 

 should be grown in forests or under the 

 shade of other trees, when efforts are 

 made to cultivate it. One reason for its 

 only occurring in forests appears to be 

 that its seeds are very thin-walled, and 

 are rapidly killed if left exposed on open 

 ground under the fierce heat of the 

 tropical sun. When artificially sown, 

 cared for, and shaded in its early stages, 

 the plant has been found in other coun- 

 tries to grow more quickly, and to give 

 better results in the open than in the shade. Similar instances are not uncommon in the plant 

 world It develops into a very large tree, sometimes more than 150 feet in height, with a 

 rather smooth, light grey bark, and easily recognised in the young state amongst other trees 

 by its peculiar branches bearing on either side a row of large leaves, generally about one to 

 one and a half feet long (see Fig. on p. 282). These branches fall off later, and are 

 succeeded by others of less characteristic form. 



The plant appears to thrive best in deep, loamy soil, near the banks of streams, and in 

 valleys, but it does not like swampy or boggy land. Like most of the rubber trees, it cannot 

 be grown with success in places where the temperature falls below about 60° F. at any season 

 of the year. A continuously humid climate is not necessary, and so far as observations go the 

 yield of rubber is greater from trees growing in regions where wet and dry seasons alternate. 

 In the past the rubber was principally collected from wild trees, and as has happened in 

 other parts of the world with other kinds of rubber-yielding plants, this led to the destruction, 

 and in places almost complete extermination, of the plant. When the plants are wild the 



By permission of Messrs. Maclaren, Shoe Lane 



NEAR VIEW OF HEVEA BRASILIENSIS 



