34 THE SCOTTISH NATURALIST 



it extracts nothing but facts." The interest and value of 

 Economic Zoology lies in that it focusses attention upon 

 the facts of animal life which have been found to be 

 intimately connected with the progress of humanity. 



In the desire to stimulate the new appreciation of the 

 value of the naturalist's labours and to spread the benefits 

 derived from them, the trustees of the British Museum are 

 issuing an " Economic Series " of pamphlets, in which various 

 aspects of the relationship of animals to man are discussed 

 by experts on the staff of the Natural History Museum. 

 In view of the great developments which have taken place 

 in recognising the links between the life-histories of certain 

 creatures and the health of their human neighbours, it is 

 not surprising to find that a large proportion of the 

 pamphlets deals with the relationship between insects and 

 disease. In this connection the characteristic features, life- 

 histories, and habits of House-flies, Lice, Fleas, Mosquitoes, 

 and Bed-bugs are described in separate pamphlets (price 

 id. each), their influence and importance as disease-carriers 

 are discussed, and the best available advice is given 

 for their destruction and control. The practical value of 

 these popular memoirs can be readily imagined when it is 

 recollected that House-flies 'are to some extent responsible 

 for the spread of cholera and typhoid fever, dysentery and 

 infantile diarrhoea ; that Lice act as carriers of typhus, 

 relapsing fever, and trench fever ; that Fleas are responsible 

 for the transmission of bubonic plague, which between 1896 

 and 191 1 accounted for upwards of 7,000,000 deaths in India 

 alone ; that, without the agency of Mosquitoes, malaria, 

 once common in Britain, and a present-day scourge of 

 Southern Europe, as well as the yellow fever of South and 

 Central America, would disappear ; and that the Bed-bug, 

 apart from its own disagreeableness, is thought to share 

 in the guilt of spreading relapsing fever and many other 

 diseases. 



The responsibility of animals in the prevalence of 

 disease among men is, however, by no means confined to 

 insects, and a pamphlet by Mr S. Hirst (No. 6, price 6d.) 

 deals with the economic importance of Scorpions, Spiders, 



