THE TROPICAL AGRICULTURIST. [June i, r882. 
The wonderfully rapid development of trade in these African rubbers is, in spite of their habit 
of growth, leading to their destruction. From two districts of Eastern Africa alone the export of 
rubber in 1880 exceeded 1,000 tons, the price having risenin one year from £140 to £250 per ton. 
Sir J. Kirk thinks the Landolphias (especially L. Kirkii) by far the most promising of 
rubber plants for cultivation in plantations ; their stems can be cut down at frequent intervals for 
the rubber, and fresh shoots readily spring up from the stools. He quotes with approval, in 
reference to the extraction of the caoutchouc, the suggestion of Mr. T. Christy (Commercial Plants 
No. I., p. 9) that the stems after cutting " could be taken to the rolling mill, and the crushed mass 
digested with bisulphide of carbon in which the rubber is soluble, but which does not dissolve 
the gum and resinous matters contained in the plant, and which if left in the rubber would injure 
its quality." 
Of other African kinds, Mr. T. Christy has sent a few seeds of a plant determined at Kew 
to be Taberncemontana crassa, and a specimen of Ficus populifolia; whilst we have F. Vogel'd also 
from Kew. 
With regard to the American rubbers, Ceara (Manihot Glaziovii) continues to interest 
planters by its rapid growth, ready propagation, tenacity of life, and early production of seed. From 
this latter quality chiefly it has resulted that the loud and urgent demand for seed has almost 
ceased in Ceylon in the course of one year. We have distributed it to several private planters in 
India and to the Government establishments there, also some to Singapore for a further trial, as 
well as to Jamaica and other colonies. 
A singletree of Hevea flowered at Henaratgoda and produced a few capsules in April. The 
growth of Para rubber is not rapid ; our largest is now 21 inches in circumference at a yard from 
the ground, an increase of 5 inches in the year. New plantations of Hevea have been formed, and 
some trees at Peradeniya have been planted in a position in the new garden where they are flooded 
when the river is high, with a view to an imitation of their native habitat. 
One plant of another species, Hevea Spruceana, which gives valuable rubber, was sent 
direct from British Guiana by Mr. Jenman, but has unfortunately not survived. 
At the request of the Government of India — at whose expense the plants were originally 
imported to Ceylon — a consignment from Henaratgoda, consisting of 28 good stocks rooted in a 
Ward's case, was despatched (from Henaratgoda) in November to the Andaman Islands. The 
climate there is likely to prove eminently suitable for Para rubber which has not succeeded in 
Peninsular India, but is going on well in British Burmah. 
The Castilloa, both at Peradeniya and Henaratgoda, also produced flowers during the dry 
weather of April ; on examination, however, these were all male. This species is said not to 
produce seed till eight years old. The finest tree at Henaratgoda has now a stem of about 22| 
inches in circumference at a yard from the ground. 
During the early part of the year I made a preliminary and tentative investigation to ascer- 
tain the condition of the milk in our Ceara trees at Peradeniya, and the best means of obtaining 
it. The principal conclusion I arrived at was that the trees had not their milk in a sufficiently 
concentrated state to invite tapping. I was quickly led to the opinion that the method of 
paring the stem as practised by the natives in Brazil (according to Mr. Cross) would not be found 
either convenient or economical. The milk-vessels occur in two layers, the richer one is in the 
innermost stratum of the bark just outside the cambium, but there is a smaller one immediately 
beneath the thin green layer ; this latter is sacrificed by the slicing process which also causes loss 
from the milk adhering to the shavings. In the culture of this kind of rubber the principal 
difficulty will, I think, be the extraction of the milk. It appears to be present in good quantity, 
but a very small amount flows from each cut, and it is difficult to avoid drip and loss if the stems 
are not perpendicular. It is not possible at present to make any estimate of the slightest value 
as to the probable average yield of a tree. The plant is evidently very hardy and rapidly recovers 
from bark injury. I think I should repeat here what I said two years ago (Notes, p. 4) that the 
yield of a few trees cannot be remunerative, and only large plantations can hope to repay the cost 
of collection. The quality of the dry rubber (resulting from milk laboriously obtained from 
one tree by small incisions) appears identical with the Ceara scrap of commerce, in spite of the 
extremely watery character of the milk. Further experiments will be shortly made. 
The more valuable Para and Central American rubbers have their milk already in a more 
concentrated condition than the Ceara ; Castilloa especially affords a milk which spontaneously 
coagulates in a few hours into a very elastic rubber. Mr. Cross states (Report to Madras Govern- 
