The native has discovered that a larger amount of rubber can be obtained at one time if the roots and stems are cut and pounded up. The result is a product known as “root rubber,” the collection of which can be justified only where the plant, from which it is obtained, develops an extensive rhizome or subterranean growth, capable of being partially removed without killing the plant. Such vines, although found in some other parts of Africa, do not occur in Southern Nigeria, and the collection of so-called “root rubber” from _L. owariensis_ only leads to the complete destruction of the plant, and should be discouraged. The small yield of latex from this species after many years of growth, and the difficulties in connection with the collection of the rubber, render its cultivation in plantations unprofitable, although planting has been attempted in the French and German Colonies. _Clitandra elastica_ is another vine said to yield a copious supply of latex, capable of being coagulated by means of heating after dilution with water. In appearance the vine is somewhat similar to _L. owariensis_, but does not appear to be common. The rubber produced from this species is reported to be of excellent quality. _Carpodinus hirsutus_, a common vine in the dry zone and on the Niger river banks, furnishes a plentiful supply of latex of inferior quality, and is made into “root” and “paste” rubber by boiling; the latter being a sticky product of the consistency of birdlime, and only saleable in Europe at a low price. The latices of _Landolphia Thompsonii_ and _L. senegalensis_ are used similarly. Both species are nearly allied to _L. florida_, which is prepared elsewhere. A number of latex-yielding plants are employed in the adulteration of good rubber, among which the following may be mentioned as the commonest: _Funtumia africana_, _Conopharyngia sp._, _Alstonia congoensis_, and _Holarrhena Wulfsburgii_. The admixture of these is usually detected by the stickiness which they impart to good rubber. The introduction of licences for permission to collect wild rubber and that of the communal plantation system, previously referred to, have rendered the position more secure than previously, and insured the preservation of the wild plants which were threatened with extinction. This has moreover been effected in the most economical manner. The results of the tappings on the Para rubber plantations in different parts of the country are of interest. In 1911 at Ebute Metta, trees eighteen years old yielded 3 lbs. 5½ oz. per tree; at Calabar six year old trees gave an average of 6 oz. per tree; while at Sapele in the same year, five year old trees yielded from 14 oz. to 1 lb. 6½ oz. per tree. In the following year the same trees at Ebute Metta gave 7 lbs. 4¾ oz., while those at Sapele yielded from 1 lb. 4¾ oz. to 1 lb. 11¾ oz. In 1915 from two Para rubber estates at Sapele 94,413 lbs. of dry rubber was harvested. (Cf. _Bull. Imp. Inst._, 1910, 1912, 1913, 1918.)