612 



The Supplement to the Tropical Agriculturist 



GOTTON-GROWBNG IN THE DUTCH 

 COLONIES. 



Amsterdam, May 13. — With regard to the 

 cultivation of cotton in Dutch Colonies, favour- 

 able reports are to hand from the West Indies. 

 Recently, too, this cultivation was also intro- 

 duced in Java. The Government is doing all 

 it possibly can do to promote the growing of 

 cotton in the district of irfamarang, and thus 

 to benefit the native population. In the dis- 

 trict of Kediii the first steps in this direction 

 have been taken, and in Djarnbi the cultivation 

 is in full progress. — L. &■ C. Express. 



STRASTS RUBBER MOTES. 



Including the trees at the old experimental 

 nursery on the hill there are 43 Para trees in the 

 garden; of these seventeen are over three feet 

 in girth, nineteen over and sever, under two 

 feet. I had expected there were more. In the 

 absence of Mohamed Haniffit was necessary to 

 train a man to tap and 21 trees were tapped and 

 35 lb. of rubber obtained. Now that a man can 

 tap without injury, this work will proceed 

 better although the drying process is difficult 

 and long, through smoking being necessary 

 owing to the damp situation of the^ garden. 

 The old Para tree supplied two pounds of dry 

 rubber making the grand total from this tree 

 37 lb. 134 oz - All the rubber is not yet dry 

 enough for sale.— Mr Ridley's Report on 1907. 



NEW RUBBER-CGNTAaNBNG PLANTS. 



Rubber (including gutta percha) is known to 

 occur in about a dozen families of plants, of 

 which the more important are the Euphorbiaceac, 

 Urticaceac (Moraceue), Apocynaceae, Asc'-epia- 

 daceae and Sapolaecae, whilst the Loranthaceae 

 and Compositae will probably also become of 

 considerable importance in the near future (see 

 Tropenpflanser, 1905, p. 633 ; and Kew Bull., 

 1906, p. 218 ; 1907, p. 285). In the remaining 

 five families the occurrence of rubber is at 

 present a matter of theoretical interest only, as 

 it has not yet been shown that its extraction 

 would be remunerative ; they are the Trochoden- 

 drnceae (Eucommia), Tiliaccae (Plagiopteron), 

 Celastraceae, Hippocrateaceae and Lobeliaceae 

 (Siphocampylus), whilst a sixth, Convolvulaceae, 

 is given by Czapek as also containing rubber 

 (Biochemie, vol. ii. p. 709). 



The presence of rubber in three African 

 species of Gymnosporia (Celastraceae) is record- 

 ed in the Notizblatt des Konigal. botanischen 

 Gartens und Museums zu Berlin, No. 42 (Bd. 

 V.), of March 11th, 1908, by Dr. Th. Loesenor, 

 who prefaces his account by a summary of our 

 knowledge of the occurrence of rubber in the 

 family. 



Radlkefer, who was the first to dotect rubber 

 in the Celastraceae, found it in the Mexican 

 genus Wimmeria (Bot. Gaz. vol. xviii., 1893, p. 

 199). The leaf _ anatomy of the Celastraceae 

 was afterwards investigated with special re- 

 ference to the occurrence of rubber by Metz, 



who irecorded its presence in special latici- 

 ferous cells of the leaves in eight species of 

 Wimmeria and in the South African Mystroxylon 

 eucleaeforme, whilst in no fewer than thirteen 

 genera, rubber was present in the form of small 

 masses in the cells of the parenchyma (Beih. Bot. 

 Centralbl. vol. xv., p 3 9), in some of these genera, 

 however, the rubber may have been present in 

 laticiferous colls in the stem and root, although 

 not occurring in special cells in the leaves; this 

 was found to be the case in Euonymus, for ex- 

 ample, by Col (Comples Rendus, vol. exxxii., 

 1901, p. 1,354). 



It is obvious that the extraction of rubber 

 could not be profitably undertaken, where it is 

 present merely in the cells of the parenchyma. 

 In the three species of Gymnosporia. investigated 

 by Loosener, however, the rubber is present in 

 special laticiferous cells, which occur in the 

 bark, the leaves and the inflorescence; but it is 

 still unknown whether the rubber is of suffi- 

 ciently good quality and present in sufficient 

 amount to make its extraction profitable. Fur- 

 ther information is also required as to the geo- 

 graphical distribution of the three species and 

 their mode of occurrence, before an opinion can 

 be formed as to the value of Loosener's dis- 

 covery. The presence of the rubber may be 

 detected by carefully breaking in two a leaf or a 

 piece of bark, when the portions remain con- 

 nected by fine elastic threads which stretch from 

 one broken surface to the other and which can 

 bo drawn out for a fair distance before breaking, 

 when they rebound and curl up. 



The three species, which are closely allied to 

 one another, are all spineless and are natives of 

 inter-tropical East Africa. Two of them, G. ama- 

 niensis, Loes., and (J. Bukohina, Loes,, are new 

 species, of which the descriptions will appear in 

 the forthcoming part of Engler's Botanische 

 Jahrbucher, vol. XL., now in the press : and the 

 third, which was described by Loosener in 1893 

 as a new species, G. lepidota, Loos. (Engl. Bot. 

 Jahrb. vol. xvii., p. 549), is now regarded by 

 him as a variety of the common and polymor- 

 phic G. acuminata, tSzysz., a native of S. Africa. 



G. amaniensis was collected by Warnecke in 

 the neighbourhood of Amani, Kast Usambara, 

 at an altitude of about 2,700 feet, and is de- 

 scribed as a relatively slender tree, attaining a 

 height of 100 feet. G. bukobina, on tli9 other 

 hand, appears to be a climber ; it was discovered 

 in 1903 by P. Conrads not far from Bukoba, to 

 the West of Victoria Nyanza, at about 4,000 

 feet. G. lepidota seems to be more widely 

 distributed than the other two even if we 

 regard it as distinct from O. acuminata, having 

 been recorded from Mts. Ruwenzori, Kiliman- 

 jaro and Mawensi. and from the Uiuguru 

 Mountains in Ukami, at altitudes varying from 

 7,000 to 11,000 feet above sea level. Accord- 

 ing to Loosener it is a tree about 33 feet high, 

 but Dawe, who collected it on Ruwenzori at 

 about 11,000 feet describes it as a shrub 10 

 feet high, and no doubt the height varies ac- 

 cording to the altitude and exposure. In the 

 Uiuguru Mountains the tree is called "Mbamala" 

 by the natives, according to Goetze. 



T, A. S, 



— Kew Bulletin, No. J 4 of 1908. 



