84 



may be seen in its interior. This oily character is caused by its 

 being collected with a flat scraper or knife moistened, as well as 

 the fingers of the gatherer, with linseed oil. 



East Indian. — In India the cultivation of the opium-poppy is 

 mainly co.nfined to three centres which afford " Patna Opium" in 

 Behar, "Benares Opium" in the North-West Provinces, and 

 " Malwa Opium" in Central India. 



The white variety of Poppy is the kind usually cultivated ex- 

 cept in Central India, the " Malwa Opium" being largely the pro- 

 duce of the purple variety of Poppy. 



The total area under Poppy cultivation in India is probably over 

 1,000,000 acres, and the Government derives a revenue of about 

 £8,000,000 from exported opium. 



For much of the information contained in these notes, which 

 have been prepared at the request of a correspondent, I am in- 

 debted to the " Dictionary of the Economic Products of India" by 

 Sir George Watt; "Subtropical Cultivations and Climates" by R. 

 C. Haldane, and "Medicinal Plants" by Bentley & Trimen. 



THE CULTURE OF THE CENTRAL AMERICAN 



RUBBER TREE, IX.* 



{Continued from Bulletin for March.) 



By O. F. Cook, Botanist in charge of Investigations in Tropical 

 Agriculture, U. S. Department of Agriculture. 



EXTRACTION OF THE LATEX OF CASTILLOA. 



Scarcely second in practical importance to a solution of cultural 

 problems is the attainment of satisfactory methods of tapping. 

 The object is not merely to avoid the destruction of the trees, but 

 to learn how the maximum quantity of rubber may be secured 

 with the least injury to future productiveness. The planter needs 

 to know how soon young rubber tress should be tapped, how the 

 incisions should be made, how close together, how large, and in 

 what direction, how often tapping may be repeated, at what sea- 

 sons, and much more. 



The first notion of the visitor from the United States is that it 

 will be a very simple matter to improve on the rude gashes made 

 by the machete of the rubber gatherer, but this has not proved to 

 be easy. The rubber milk is not the sap of the tree and cannot 

 be drawn out by boring holes in the trunk, as is done with the 

 sugar maple. The milk does not pervade the tissues of the tree 

 but is contained in delicate tubes running lengthwise in the inner 

 layers of the bark, and to secure milk in any quantity it is neces- 



* Extnict from the U, S. Department of Agriculture, Bull. No. 49. Bure«u of 



Plaut IndiiBtry. 



