188 A NATURALIST IN THE GUIANAS 



Hevea. It appears from Dr. Small's studies that the 

 species come nearest to Micranclra siphonioids of Brazil, 

 but that it is probably different, and most likely is an 

 undescribed species. All the Micrandras hitherto known 

 are Brazilian.' 



With respect to the rubber itself the following report 

 was sent us : — 



' Keport on Three Samples of Orinoco Eubber, by 

 John Murphy, Supt. Gutta Percha and Rubber 

 Mfg. Co., Factory, Brooklyn, New York. 



' This rubber is of good quality and clean, and if 

 properly cured would class very nearly with medium 

 Para. At present I consider it fully equal to good coarse 

 Para. 



* The rubber vulcanises readily and well ; I find no 

 material difference between the samples as to quality, 

 but there is a difference in regard to shrinkage, as 

 follows : — 



' Sample A lost 17 per cent. 

 C 21 



„ B „ 32 „ 

 Sample A represents the pressed thin sheets. 



„ B ,, „ wet clean unpresscd sheet or 



ball. 

 „ C „ „ scrappy ball.' 



I have entered into all these details here because 

 rubber is to-day required for so many important indus- 

 tries that the discovery of fresh sources of supply cannot 

 fail to interest a large number of people. Unfortunately, 

 under existing circumstances 1 do not believe that the 

 successful exploitation of the forests on the Nichare 



