NOTES ON ECONOMIC PLANTS, 303 



by the disease. Should it prove as well adapted to our soil 

 as Coffea liberica does, keep free from disease, and have a 

 distinct cropping season, it will no doubt supersede all other 

 kinds in the Straits. 



Arabian Coffee [Coffea arabica). — The Arabian coffee 

 planted in the Nursery Hooks healthy, but grows slowly. 

 Hybridization may probably re-establish it in cultivation. 



Bengal Coffee [Coffea bengalense). — The growth made 

 by Bengal coffee does not look promising, the plants are still 

 small how r ever and may not shew their true character. 



Chocolate (Theobroma cacao). — Some plants of Chocolate 

 which stood for some years leaf-eaten, extremities of the 

 branches dead, and looking in a dying state had, on the land 

 coming under the control of the Forest Department, a num- 

 ber of Dadup trees planted among them for experiment. The 

 Dadup trees have now grown to about twenty-five feet in 

 height and their branches having nearly met, the solar rays 

 are prevented from striking the Chocolate plants directly. 



The result has been that the latter have thrown oft their 

 lethargy and started into determined competition for light with 

 the Dadups and have grown remarkably, the insects have given 

 up attacking the leaves, and robust health has returned to 

 them, but on other plantations where the plants have had 

 shade from their infancy they have mostly died. 



The Chocolate plant has proved verycapricious in the Straits, 

 whole plantation going off without any apparent cause except 

 the attacks of leaf insects, while here and there a solitary 

 plant will for many years survive its fellows and go on bearing 

 heavy crops of fruits. It has been said that animals or plants 

 located in large numbers together are liable to epidemic 

 disease, which looses its grasp only after the individuals are 

 thinned down to health permitting numbers. There is doubt- 

 less such a law in nature. What seems required is a know- 

 ledge of how far one can safely go without danger of calling 

 its working into activity. 



TEA [Assam hybrid) grows with a freedom which would 

 seem to insure profitable cultivation, the question is more one 

 of cheap manipulation than of plant growth. 



