254 



In addition, the mayor and council of the city enacted a by-law 

 November 11, 1907, one provision of which made it unlawful for any 

 boat entering the port of Vancouver to be connected with any 

 wharf hi the city by a gangway which was not guarded by some 

 person there for the purpose of preventing rats from leaving such 

 port by such gangway. 



NECESSITY OF CONCERTED ACTION OF NATIONS. 



It appears from the foregoing data that a more or less widespread 

 crusade against rats is being carried on hi the different ports of the 

 world, and that the extent and persistence of these measures, with 

 few exceptions, depend upon whether the particular port has been 

 directly threatened with an invasion of plague. It is necessary to 

 state here that the above data are not presented as a complete 

 epitome of measures taken throughout the world, but refer to the 

 ports from which consular reports were received. 



The fact that within fifteen years plague has spread to no less than 

 52 countries indicates that the measures taken against rats have not 

 been wholly efficient. 



It is too much to expect that the rat population can ever be ex- 

 terminated from any country, but by the adoption of systematic 

 measures, such as are hi force in Denmark, the rat population should 

 be markedly reduced, and the occurrence of plague among rodents 

 quickly detected. It is not too much to expect, however, that ocean 

 carriers could be freed from rodents and kept so, and this action would 

 confine plague within continental boundaries. 



When the existing sanitary conventions were adopted several years 

 since, the importance of the subject was just beginning to be recog- 

 nized, but now that the rat has been proven beyond all doubt to be 

 the greatest factor in the transmission of plague from one country 

 to another it would appear that the conventions in question should 

 be amended, and the Surgeon-General of the Public Health and 

 Marine-Hospital Service, in a communication of February 26, 1909, 

 addressed to the Secretary of State, suggested the advisability of 

 submitting the question of the systematic destruction of rodents 

 aboard ships to an international sanitary conference with the view 

 to the adoption of an international sanitary regulation on the subject. 



It must be apparent that such a regulation would lessen quarantine 

 restrictions, prevent the destruction of cargo by rodents, and in large 

 measure obviate the danger of the further spread of plague. 



r 

 o 



