Burbidge remarks that there are many milk-yielding species of Ficus in the Bomean forests, which, with careful experiment, may possibly be made to contribute remunerative quantities. The Malayan representatives of the Artocarpem also deserve exarnination.
According to Murton, the gutta-sing-garip of the Malay Peninsula is identical with the gutta-susu of Borneo. There are two varieties of the plant producing it : one has a very dark-coloured outer bark, with lighter-coloured warts, and red inner bark ; the other has a light cork-coloured outer bark, with longitudinal channels, and light-yellow inner bark. The produce of the former is considered superior. The stems are sometimes cut down, but are generally ringed at intervals of 10-12 in., and the milk is allowed to run into vessels made of palm-leaves or coco-nuts ; the flow continues for some time, but after 10 minutes, the substance is very watery and thin. One plant will yield 5-10 catties (of lb.) of coagulated rubber. When raw, the juice has the appearance of sour milk; it is coagulated by the addition of salt or salt water, and resembles Bornean gutta susu in all respects.
CEARA..—The rubber known in commerce as " Ceara scrap " is produced by a distinct species from the other Brazilian and Central American rubbers, which has been narned Manihot It is a tree of 30 ft. in height, with a dense rounded crown, and attaining a diameter of 4-5 in. in 2 years. lt grows wild in the flat country of Brazil running inland from the coast-tovvn of Ceara, in 4° S. lat., mostly, so far as is known, at an altitude of about 200 ft. The district possesses a very dry arid climate for a considerable portion of the year ; the rainy season lasts from November to May-June, when torrents of rain fall for several days in succession, followed by flue weather. There are years when scarcely any rain falls. The daily temperature avenges about 82°-90° F. The soil frequented by the tree is sandstone, gravel, or granite, its dryness aud poverty being indicated by absence of all ferns, weeds, grasses, and mosses.
The native system of bleeding the trees and collecting the rubber is sufficiently simple. The collector comrnences by sweeping away loose stones and dust from around the foot of the tree, and spreading some large leaves to receive the milk as it flowa from the tree. The outer surface of the bark of the trunk is then stripped off to a height of 4-5 ft., as shown in Fig. 1173, and the milk exudes and runs down in rnany tortuous courses, a portion usually falling upon tbe ground. After several days, the juice becomes dry and solid, when it is pulled off in strings and rolled up in balls, or put into bags in loose masses. The paring should only be deep euough to reach the milk-ducts, which reside in the middle layer of the bark ; but this circumstance is seldom regarded by the collectors, and many trees are prematurely destroyed by the careless wounding of the wood. The operation is conducted only during the dry season.
The habits and habitat of tbis plant immediately pointed it out for cultivation in a systematic manner in some of our warmer possessions, and the success attending the experiments is the more desirable since the late drought in Brazil caused the death of immense numbers of the tree. It has proved itself to be well adapted for culture iu Ceylon, Upper India, Zanzibar, and Jamaica, but the climate of the Malay Peninsula is too moist for it. The experience gained thus far in its cultivation may be briefly stated. Seeds are early produced, if the tree is not shaded. They should be buried
in brown sand, and kept moist until there are iodications of growth, when they may be planted out permanently. In some situations, where the ground is rough and strong, they alight be sown broadcast. Plantations may also be formed by cuttings, which take root as easily as a willow. They should be from the points of strong shoots, and about 1 ft. in length. In planting, each cutting may he put down in the soil to a depth of 6 in. If scarce, the entire shoot may be cut into pieces, each possessing a bud, all of which will grow if covered with in. or so of s.d1. On loose sai lily JCOil le, or exhausted coffee land, plantations may be formed at little expense. Hard, dry, gravelly wastes, if found to support any kind of bush, arc also suitable sites. Holes might be made in strong land with an iron jumper, and a stout cutting put into each, and filled m.ith pelddes. On bare or thinly covered portions of rock, the cuttings might be laid down flat, and a little heap of stones, or any kind of (16bris, about the size of a piled over each, care being taken that the extreme point of each cutting with a bud is left uncovered. Wherever there is any sort of stunted tree or shrub vegetation, with an occasional sprinkling from a monsoon shower, the tree is likely to prosper. There can be no doubt of the hardiness of the species, its readiness of culture, and adaptability to circumstances. It grows quite as readily from seed as from cuttings, and, though a native of a tropical sea-level, thrives well in Ceylon up to at least a level of 3000 ft., and on the most barren soils. It would seem especially adapted for the dry and barren districts of the E. and N. provinces of Ceylon, or in the higher districts; but it would not be wise to risk it in localities wbere the teruperature is liable to fall below 60° F.
The seed-c,oat is of remarkable thickness, and very hard, and the natural process of germination occupies, it is said, more than a year. All that is necessary to hasten this, is to assist the seed-coat in splitting, which is best effected by holding the seed firmly, and rasping off with a file both edges at the radicular end, recognized externally by pssessing at its side a flat two-lobed appendage, technically known as the caruncle. It is best not to file off the actual end, as the radicle of the embryo may then be injured. After this treatment, properly performed, the young plant appears above ground in 2-3 weeks. The seedlings require no particular attention. They grew rapidly, and may be finally planted out at distances of 20 ft. The trees at Peradeniya (Ctylon) flowered ut the age of 18 months ; 2i years, the larger ones formed branching trees about 25-30 ft. high, with a stem 1 ft. 9 in. in circumference, at a yard from the base, and a smooth, silvery, birch-like bark, readily peeling off. The best system of tapping the trees under cultivation has yut to be proved. Some improved methods arc described later on in the present article (see p. 1666).
This rubber is considered almost next to Para in value, being dry, very elastic, and free from stickiness; its one drawback of containing wood and other foreign matters, in such quantity as to cause a loss of often 25 per cent. in washing, may doubtless be altogether removed by the exercise of care in the collecting.