IN THE VICTORIAN ERA 29 



this manner transferred to other materials upon 

 which they may alight, just as Pasteur showed 

 many years earlier silkworms can communicate 

 the fatal plague of pebrine by crawling over each 

 other's bodies, carrying in their disease-laden feet 

 the infection from one worm to another. During 

 the recent outbreak of bubonic plague in the East 

 the part played by flies in disseminating the virus 

 has been repeatedly emphasised. Yersin was the 

 first who called attention to the presence in large 

 numbers of virulent plague bacilli within the 

 bodies of flies which he collected in the vicinity 

 of plague-stricken persons, and it was found that 

 flies which had fed on plague-infected material and 

 were then isolated lived for several days after- 

 wards, during which time virulent plague bacilli 

 were present in their bodies in immense numbers ; 

 thus were these insects converted into winged 

 messengers of evil of the most repulsive type. 



I am not aware whether any experiments on 

 the vitality and transmissibility of diphtheria and 

 consumption germs by means of flies have been 

 made ; but in view of the overwhelming evidence 

 of the culpability of these insects in spreading 

 plague, it is not unreasonable to presume a re- 

 sponsibility on their behalf in regard to other 

 diseases ; indeed, in the report issued by the Army 

 Medical Commissioners of the Spanish-American 



