252 INJURIOUS AND USEFUL INSECTS 



fornia have been saved from ruin by the discovery of 

 methods of exterminating scale-insects, and the new industr)' 

 of dried figs (which entirely depends upon fertilisation by a 

 minute Hymenopterous insect) has been set up in California 

 by the labours of the Department of Agriculture.* Pasteur's 

 experimental researches upon the diseases of silkworms restored 

 an industry of the first importance, which was threatened 

 with total extermination. The damage done to British hides 

 by the warble-fly has been estimated at several million pounds 

 a year, but so inadequately has this insect been studied that 

 we do not know for certain where the eggs are laid, and which 

 part of the ox is to be protected from the fly. England needs 

 such national laboratories as those of the Department of 

 Agriculture in Washington, or the Departments of Agricul- 

 ture and Forestry in the Gesundheitsamt in Berlin. The 

 cost of these establishments is much more than repaid by 

 the benefits which they secure for agriculture, and we ought 

 to regard it as one form of that wise expenditure which is true 

 economy. 



* Dr L. O. Howard on Smyrna Fig Culture in the United States. 

 Yearbook of the United States Department of Agriculture, 1900, p. 78. 



