GNAWING ANIMALS RODENTS 135 



the eminent and learned lecturer to the London 

 School of Tropical Medicine. He says : " I have 

 endeavoured on several occasions to draw attention 

 to the part played by blood-sucking and other house- 

 hold vermin in the transmission of such diseases as 

 measles^ smallpox^ typhus fever, scarlet fever and 

 mumps/^ 



Rats, cats, dogs, fowls and man each are attacked 

 by different fleas, and although it is popularly said 

 that no flea but Pulex irritans will bite man, this 

 theory is erroneous. The peculiar fleas of all these 

 animals bite man and may become disease carriers. 



It were a hopeless task to attempt the total exter- 

 mination of rats. A price has been on their heads 

 or tails for centuries. Wholesale slaughter does but 

 secure more favourable conditions for the multiplica- 

 tion of the survivors. What we want is knowledge, 

 and in addition to knowledge a judicious, thoughtful 

 and constant application of it. During periods of 

 alarm, as that of the autumn of 1910, when East 

 Anglia was threatened with rat plague, a storm of 

 public opinion is excited, which too often dies away 

 before any permanent precautionary measures have 

 been established, to revive only when the evil has 

 again grown to menacing proportions. 



Our buildings, wharves and quays should be rat- 

 proof. All rats on ships hailing from infected ports 

 should be destroyed and not one allowed to land. 

 The destruction of the rats only is not sufficient; it 

 must be so arranged as to secure the annihilation of 

 their fleas, suffering none to escape. 



The fact that rats are the carriers of plague was 



