EXPLANATION OF YELLOW FEVER ON SHIPS 1^1 



stegomyia larvae and eggs which developed during the 

 voyage into the winged insect. Tlie sliip then became 

 like a house in a yellow fever town ; the particular 

 species of mosquito — the stegomyia — was there. All 

 then that was necessary to ligiit up an epidemic on 

 board was that a labourer or some one from shore 

 suffering from the disease should come aboard, or that 

 a member of the ship's crew sliould go ashore and 

 contract the disease. Soon after the ship sailed 

 the infected man naturally developed the disease, 

 and presently every mosquito in the whole ship would 

 become infected ; and then most of the crew would be 

 down with yellow fever. Tliere is no necessity to search 

 for a miasm nor to ask us to discover a sea mosquito, as 

 Dr. JNIanning suggests, for an explanation of this now 

 well-known fact.^ That the stegomyia can and does 

 develop in fresh water on shipboard in warm latitudes 

 as easily as it can ashore is now well known, and if it 

 can transmit yellow fever ashore, it certainly can do so 

 on board ship, which is to all intents and purposes a float- 

 ing house. But no, in spite of all these explanations, 

 tradition and yellow fever houses sind J iiju still cling. 

 Although yellow fever and malaria have been 



' To show how Iiistory repeats, as recently as 1908 a small epidemic of 

 yellow fevef occurred at St. Nazaire a week after the arri\'al, on Sep- 

 tember 24th, of the S.S. La France from Martinique, which badly infected 

 island she had left on September 10th. The cases occurred only amongst 

 those working the ship and only after the discharge of the cargo, amongst 

 which there was a large consignment of banana bunches. In the latter 

 infected stegomyia which came on board at the port of departure remained 

 hidden and quiet until during the discharge they were disturbed, wlien they 

 sought refuge in the cabins and commenced to bite the men working and 

 sleeping on the ship, with the result of a typical small epidemic, absolutely 

 contined to those working the sliip. 



