however, at the head-waters of some rivers, they also live and 
develop themselves perfectly well in dry and elevated land. In 
the Amazonic forests, the average proportion is of one hevea-; 
tree for 80 trees of other species. 
The milky latex circulates from the root to the leaves, exist- 
ing, however, in greater abundancy in the trunk, up to a height 
of abou: 2 metres from the ground. The heveas in Brazil are 
generally known by the term “seringueiras” and the forests in 
which they are found are denominated “seringaes.” 
The average production of a “seringueira” during the 
harvest season, which extends over the space of 6 months, is 
of 5 kilos of fine rubber and 750 grs. of sernamby. 
The species most appreciated besides the hevea braziliensis, 
are the hevea de terra firme, of which Dr. E. Ule treats in his 
recent studies, and which are found on the frontiers of Matto 
Grosso, the hevea do Rio Negro, called “seringa. verdadeira” 
(the real seringa), the hevea benthamiana and the hevea dukei, 
Hub, from the region of the Japura, all of them furnishing ex- 
cellent products. 
In the valley of the Amazon exist the micandras, belonging 
to the same family and producing a rubber of a superior quality, 
since it is sold under the name of Fine-Para. The production 
of these trees goes to the market includéd in the category of 
hévea, owing to its similarity to this latter. The micranda 
syshenoide which is the most known species, is found on the 
Lower Amazon, in the innumerable islands at the estuary of 
the great Amazon River: in the valleys of the Madeira, the 
SolimGes, the Japura and the Purts; the natives give it the 
names of tapygu, curupita murupita and seringarana. .They 
are leafy reg hliose trunk is of from 0™80 to 1™ in diametre and 
from 20 to 2 metres high. They grow as well in the low lying 
marshy soil as in the elevated lands, whence comes their denomi- 
nation of tapuru da vargem and tapuru de terra firme. The 
tapuri is as lactescent or milky as the hévea and the latex 
which it renders is equally rich, seeing that it gives 50 per cent. 
of fine rubber. \ 
The trees whose product, the caucho, occupies the second 
place in the general exportation of rubber from Brazil although 
as a matter of fact it only commenced to come into the Brazil- 
ian markets in the year 1896, belong to the family of the 
Ulmaceas. These are the Castillas which up till a short time 
ago have been classed as of the same species as that which 
grows in Mexico and Central America—the Castilla: elastica, 
but studies made by professor O. Warburg show that they age 
distinct species which was thence forward denomiyated 
Castilla Ulei, Warb. vi ema 
15 
