REPORT ON THE CAOUTCHOUC OF COMMERCE. 
45 
same genus, as they furnish good Caoutchouc, capable of much 
improvement, and the tree is easily cultivated. 
Of the remaining plants, I should also strongly recommend the 
introduction of the Apocynaceous climbing plants, viz., TJrceola 
elastic a, Roxb., Valie<B r sps., TVilhiglibeia edulis , and the species 
of Landolphice . 
The TJrceola elastica , Roxb., has long been known, and is said to 
be ready to tap after the third year’s growth, and when cut down 
soon to spring up again. 
The species of Vahece which yield Madagascar Caoutchouc are very 
valuable sources of supply. Although this variety of Caoutchouc is 
comparatively new to English commerce yet it speedily has had its 
good qualities recognized, and now stands next that of Para in value. 
The Willughbeicc and the Landolphice are very near to each 
other, and may, when better materials for comparison exist, even 
prove generically the same. They are easily cultivated and are 
susceptible of much improvement. 
Climatic conditions necessary. — As to the climatic conditions 
existing in India, isomeric with those under which the species re- 
commended to be introduced exist in their habitats, Upper Assam 
seems to be remarkably well adapted, as the conditions under which 
the Ficus elastica best thrives are exactly those required more or 
less by all Caoutchouc yielding plants. Speaking of the cultivation 
of the Ficus elastica , Roxb., Mr. Mann describes the whole country 
of Upper Assam as resembling one extensive basin of diluvial and 
alluvial deposit, and that very rich and excessively moist plantations 
could be got up easily. 
With special regard to the Ilevece , Dr. Spruce writes me that 
they thrive best at or near the sea level, in a mean temperature of 
78° to 80°, and that does not pass the limits of 70° to 90°; in a 
humid climate where there are rarely 10 days together dry even in 
the (so called) dry season, and that they are trees of the primitive 
forest or river margin, never found in savannahs. Ceylon, Malacca, 
and some parts of Romeo, from what he has read, come nearest to 
the Amazon districts. However, I leave the comparison of climatic 
conditions to those who know India well, only recording my opinion 
that I believe the Castilloa elastica and the climbing plants would do 
well in Upper Assam, and the Ilevece almost, if not equally as well. 
Results to be expected.— The tree kinds could be safely tapped at 
twenty -five years of age, and their produce if collected and prepared 
as I have intimated would realise a handsome profit. The climbing , 
