BIOLOGICAL PROBLEMS 



A classic example is that afforded by the ruin of 

 the coffee industry in Dominica and Ceylon. 



In 1841 78,685 acres were under cultivation for 

 coffee in Ceylon. From 1855-82 coffee was the staple 

 export industry of the colony, reaching the maximum 

 in 1875, when almost 1,000,000 hundredweight of 

 coffee, valued at over ^2, 000,000 sterling, was ex- 

 ported. About 1870 the plants began to be noticeably 

 attacked by a fungus, Hemileia vastatrix, the coffee- 

 leaf disease, which spread steadily and irresistibly 

 over the vast sheet of coffee plantations in the moun- 

 tains, and was disregarded until too late. By 1880 

 the industry was threatened and the planters in great 

 distress; it soon collapsed utterly. Not only did 

 this react on the customs and rail receipts, but in- 

 directly it ruined more or less subsidiary industries 

 which depend on planting, and impoverished thou- 

 sands of natives of all classes, as well as the planters 

 and the mercantile community of Colombo, who are 

 mainly dependent on the trade created by the plant- 

 ing industry. Ceylon has now ceased to be a coffee- 

 exporting country. Some years previously the coffee 

 industry in Dominica had been wiped out by this 

 disease. 



In a national emergency we can deal only with 

 the most insistent and troublesome pests injurious to 

 the production of vital economic products. During the 

 war two plagues of vegetable life have come into pro- 

 minence through the destruction caused to food. First, 

 the plague of caterpillars and other insect pests which 

 for two years in succession has caused havoc in the 

 fruit-farm and orchard, and, second, the dreaded blight 

 of potatoes which followed the introduction of the 

 potato plant to Britain by some three hundred years. 



The first serious onslaught of this disease, which 

 swept over Europe with dramatic suddenness, has 



