Ficus elastica.—

The future supply of India-rubber being a matter of so much interest, it will be interesting to note Mr. Mann's operations in the cultivation of this important species in Assam, which are detailed in his report for 1876-77, received at Kew at the beginning of last year:—

"The planting of caoutchouc-trees has not as yet emerged altogether from the experimental stage, for although no doubt remains that the tree will grow most luxuriantly in the locality chosen, the different ways in which the young trees have been planted did not all succeed equally well. The plants planted in cane baskets in the forks of trees, although many of them are alive and healthy, remained stationary, or almost so. Many of the trees planted simply in the ground also did badly, and there is no doubt that Rubber-trees should not be planted in this way.

"The trees planted on low split stumps or in earthenware cylinders on low stumps of trees, on piles of wood put crossways and mixed with earth, and on small mounds of earth about 2 to 3 feet in height, have all done exceedingly well; all plants will in future be planted on mounds of earth, stumps, piles of wood, or what-ever is most handy, raised about 3 feet from the ground."

Mr. Mann found that the best cuttings do not transplant so well as seedlings, and that raising plants from seed is the method of propagation which must be chiefly depended on.

In a subsequent report, which reached Kew at the close of last year, he gave further particulars of this enterprise, explaining, amongst other matters, that "drainage about the roots is insured by planting upon mounds." The total area under cultivation at Charduar was page 39 572 acres, 112 acres additional having been cleared for planting.

2. Fijian India-rubber.—

In the last Kew Report (pp. 31, 32) reference was made to two plants from Fiji which were said to produce rubber. One of these was identified with certainty as Alstonia plumosa. The other was referred with doubt to Tabernæmontana pacifica.

From ampler materials collected by Mr. Horne, the Director of the Botanic Garden, Mauritius, during his visit to Fiji, it appears that the plant described by Seeman under the latter name is probably not really itself distinct from Alstonia plumosa, and it is therefore not improbable that both the caoutchouc-yielding plants in Fiji belong to this species.

Two other species of Alstonia also yield caoutchouc. One of these is A. scholaris (see Journ. Soc. Arts, 1864, p. 30), which is widely distributed through the tropics of the old world. The other is A. costulata, a native of the Malayan archipelago, which is described by Maingay as "abounding in pure caoutchouc."

3. Hevea in British Guiana.—

Mr. Prestoe, Government botanist of Trinidad, whose mission to British Guiana has already been adverted to, informs me that he met with a species of Hevea at the penal settlement on the Mazaruni river. Mr. Prestoe writes to me:—"The three plants you kindly sent me last year enabled me to detect the tree on two islands in the Essequibo—of course at a distance. I secured some 50 seedlings. Darkness and the departure of the steamer prevented my doing more; but I have no doubt, from what I saw, that this tree exists in the forests of Guiana in unbounded plenty. Some of the leading colonists knew of the India-rubber being sometimes collected by the Indians, but I met with no one who had any notion of the tree producing it, the supposition being that it was produced by a species of large-leaved Ficus."

Mr. Prestoe forwarded leaves of the Hevea collected by him. It is identical with a plant collected in British Guiana by Dr. Hancock, and is probably Hevea pauciflora. It is remarkable that the existence and uses of so important a plant in the forests of British Guiana should have so long remained in oblivion, and Mr. Prestoe's detecting it during his brief visit to the colony is an instance of the services which botanical science in the hands of an energetic official can render to colonial industry. The matter is of the more importance since the exportation from the colony of Gum Balata, which at one time attracted considerable attention, has now almost ceased.

4. Liberian Rubber.—

Mr. Thomas Christy has introduced a new rubber plant to this country from Liberia, which we succeeded in identifying at Kew with Urostigma Vogelii, a species first collected at Grand Bassa by Vogel, and described in the Niger Flora. It belongs to the same family as the fig. The rubber is made up into balls about the size of a large orange. It is valued in the London market at Is. 6d. per lb., and if sent home cleaner would command a higher price.

5. Malayan and African Rubbers.—

These products have the point in common that they are produced by nearly allied, though distinct, climbers belonging, like Alstonia referred to above, to the natural family Apocynaceæ. Much information about them, accompanied by specimens and sketches, has been received at Kew from Mr. Murton, Superintendent of the Botanical Garden, at Singapore, page 40 Mr. Burbidge, during his travels in Borneo for Messrs. Veitch, Mr. W. H. Treacher, the Administrator of Labuan, and Dr. Kirk, Her Majesty's Consul-General at Zanzibar. The complete study and examination of these materials has not yet been completed, and the results will be given in the next Kew Report.