6 ON THE COMMERCIAL KINDS OF INDIA-RUBBER. 
were round and smooth, and the bark was of a light colour and not very 
oblong, ovate shape, the centre one rather more than a foot in length, and the 
others a little shorter. We found also the fruit of the Seringa ; itis ligneous ; 
the size of a large peach, and divided into three lobes, each of which contains 
a small black nut.” 
Of the caoutchouc obtained from South America, the best and most 
valuable is that known as Para india-rubber, the produce of Hevea 
Guayanensis, Aub, (Siphonia elastica, Pers. ; S. Cahuchu, Willd.), and 
other species of the same genus. In a paper in the ‘ Kew Journal of 
Botany’ (1854, p. 369), by Mr. George Bentham, on plants collected by 
Dr. Spruce, the following notes occur on the subject :— 
“ Siphonia Brasiliensis, Willd. (Hevea Brasiliensis, Muell). In the forests 
of Para. A lofty handsome tree, branching from the base, and yielding the 
caoutchouc the most abundantly exported.” —R. Spruce. 
lutea.—From the forests of the Rio Uaupés. A tree of 70 feet ; the 
milk copious, speedily turning black, and staining linen permanently. When 
dry, elastic and very tenacious.” —R. Spru 
* S. discolor.—Scarcely elastic when dry.”—R. Spruce. 
“ S. paucifolia.—A large tree, 40 to 50 feet high, yielding a copious milky 
"uice." — R. Spruce. 
* This genus seems abundant throughout the Amazon, but not all the 
cies yield caoutchouc (or xiringue, as it is here called) of good quality, those 
of the Gapó and Caatinga producing a brittle gum."— R. Spruce, ms. 
In a paper by Dr. Spruce on the india-rubber of the Amazon (Kew 
Journ. Bot. 1855, p. 193), he says:— 
* On the upper Rio Negro and lower Casiquiare are two species —Siphonia 
lutea, Spr., and S. brevifolia, Spr., known respectively as the long-leaved and 
short-leaved Seringa. The former yields most milk, but neither are so produe- 
tree of S. brevifolia, near San Carlos, which measured 110 feet, I first saw 
and gathered S. lutea in the mouth of the Uaupés ; and as I came down the 
In a letter received in last October, Dr. Spruce kindly informs me 
