154 THE USES OF PLANTS. 



1870 was no doubt owing to the general adoption of 

 the process of vulcanizing. Until the introduction, a 

 few years ago, of the remarkably cheap and protean 

 material known as CELLULOID, the useful, and even 

 necessary, appliances to which Rubber or Vulcanite 

 alone was applicable seemed practically infinite. 

 Naturally the Tropics, where alone the trees seem 

 to produce the abundant latex required, have been 

 ransacked for new Rubber-yielding species. These 

 seem to grow mainly between the isotherms of 70 F., 

 where the annual rainfall is about 90 inches. The chief 

 kinds in commerce are American : Para, Carthagena 

 (from New Granada), Ceara ; West Indian: Guaya- 

 quil, from Ecuador, Pernambuco, Maranham, Nicar- 

 agua, Honduras, and Guatemala; Asiatic: Singapore, 

 Assam, Penang, Java, Siam and Borneo; and African: 

 Madagascar and West Coast. Of these, the PARA, 

 or CAHOUT-CHOU,from the Amazon valley, is the most 

 valuable. It is the produce of Hevea guianensis, Aub., 

 brasiliensis, Mull. Arg., Spruceana, Mull. Arg., /#&'- 

 folia, Mull. Arg., rigidifolia, Mull. Arg., and discolor, 

 Mull. Arg. CEARA RUBBER is derived from Manihot 

 Glaziovii, Muell. Arg. ; that of Pernambuco from 

 Hancornia speciosa, Gomes, the MANGABEIRA RUBBER- 

 TREE. The WEST INDIAN RUBBER comes from the 

 mainland, and is the produce (as is that of Carthagena, 

 Guayaquil, Nicaragua, Honduras and Guatemala, 

 known as the 'Ule group') of Castilloa elastica, Cerv., 

 and C. Markhamiana, Collins, the latter discovered 

 in 1872. The caoutchoucs of Assam or Sylhet, and 

 probably Singapore, are derived from Ficus elastica, 

 Roxb., F. laccifera, Roxb., and F. hispida, Roxb., and 



