Agricultur. — Horticultur. — Forstbotanik. 351 



That since shape^, colour, and specific gravity of root or of juice 

 are shown not to be correlated with percentage of dry matter, sugar or 

 nitrogen, selection for these characters is not likeiy to lead to any im- 

 provement." R- H. Lock. 



Wright, Herbert, Hevea brazlUensis orPara Rubber. Its 

 botany, cultivation, chemistry and diseases. 

 (A. M. and J. Ferguson, Colombo. 10b and Vll pp. With 

 28 plates. 1905.) 



The first plants of Para rubber were received at Heneratgoda, 

 Ceylon from Kew in 1S75, having been raised from seed collected by 

 Mr. Wickham in the Ciringals of the Rio Tapajos. Propagation, 

 first by cutting and later by seed, was carried on and now there are 

 some 40 000 acres of this plant in Ceylon whilst large quantities of 

 seed have been distributed to many parts of the world. Although at 

 first it was thought that Hevea should be planted in places but little 

 above the sea level it has been shown that it will grow up to 2,000 feet 

 and even higher in some districts of the Island. The laticiferous System 

 is briefly described and the functions of latex discussed. 



At Para itself there is a rain-fall of 80 to 120 inches and a mean 

 temperature of 75 to 81" F., and allthough it is pointed out that these 

 conditions are not absolutely necessary for the cultivation of Para rubber, 

 many parts of the tropics possess them and in these areas ihe industry 

 promises to become as important as in Ceylon, the Malay Penin- 

 sula and I n dia. 



The cultivation of the plant is dealt with in detail, and illustrated 

 by views of trees grown in various conditions, e. g. drained swampy 

 lands. rocky hülsides etc. With wide planting coffee and cacao can 

 be grown with success amongst Hevea, whilst as „catch crops" for the 

 first few years, Ground nuts {Arachis hypogaea), Cassava {Manihot utl- 

 lissima) and lemon grass {Andropogon), have given good results. 



A chapter is devoted to soils and manuring. Three chapters treat 

 fully of the important question of tapping. The härm done by bad tapping 

 by whijh the wood is injured is illustrated. Various patterns of tapping 

 instruments are described and illustrations given of several ; Golledge's 

 knife, and Bowman's and Northway's Knives are spoken of as 

 having given good results. The use of scrapers of any kind is depre- 

 cated on the ground that in practice they tend to clog.the freshly opened 

 latex tubes. There are four principal methods in vogue of tapping trees, 

 a) Single oblique lines, b) V-shaped incisions, c) Single oblique cuts 

 joined by a vertical Channel; known as „half-herring-bone" when all the 

 cuts are on one side of the vertical line and „füll herring - bone" 

 when on both sides, d) spiral curves. The advantages and dis- 

 advantages of the various methods are discussed. Owing to the 

 favourable results obtained^ the last method has recently gaincd favour 

 in Ceylon and elsewhere. The main stem is practically the only pari 

 of the tree to be tapped and the greatest yields are obtained from the 

 lower portion. up to six feet from the ground level. Some doubt appears 

 to exist as to the quality of the latex obtained from higher levels and 

 contradictory results are reported from different localities. It is most 

 important in practice to take advantage of what is now generally known 

 as the „wound response" which is usually obvious within 24 to 48 hours 

 after the first tapping. In an experiment quoted the yield of latex ob- 

 tained from the same number of incisions, over approximately the same 

 area on one tree, increased from 61 cc. on the first tapping to 449 cc. 

 on the fourteenth tapping, about two and a half months later. Tapping 

 every day either for the whole of the rainy season or during alteinate 

 months has given excellent results on a large scale on several Ceylon 

 estates. Trees to tap should, in Ceylon_, be not less than 20 inches in 

 circumference 3 feet from the ground and at least 4 to 6 years old. 



