YELLOW FEVER INSTITUTE 



Treasury Department, Bureau of Public Health and Marine-Hospital Service. 

 WALTER WUHAN, Surgeon-General. 



Bulletin No. 14. 



Section B.— ETIOLOGY. P. A. Surg. M. J. ROSENAU, Chairman of Section. 



EXPERIMENTAL STUDIES IN YELLOW FEVER AND 



MALARIA. 



By M. J. Rosenatj, Passed Assistant . Surgeon, 



Herman B. Parker, Passed Assistant Surgeon, 

 Edward Francis, Assistant Surgeon, 

 George E. Beyer, Acting Assistant Surgeon. 



THE CAUSE OP YELLOW EEVEK. 



The cause of yellow fever is not known, but we have to consider 

 the- Myxococcidium stegomyice of Parker, Beyer, and Pothier. 

 These authors described in some detail the life cycle of a supposed 

 animal parasite in infected mosquitoes closely resembling coccidia. 



It was our first duty to investigate the merits of this announcement. 



We therefore first sectioned about one hundred normal mosqui- 

 toes, Stegowyia and Cidex, both male and female. A study of these 

 slides soon convinced us that bodies resembling Myxococcidium stego- 

 myiae may be found in normal mosquitoes and that for the most part 

 these bodies were yeast cells in various stages of reproduction. Car- 

 roll had called our attention to this in a conversation and subsequently 

 discussed it in an article published in the Journal of the American 

 Medical Association for November 28, 1903. 



Since then the French commission, working at Rio de Janeiro, 

 has come to the same conclusion. 



a Marchoux, Salimbeni, and Simond : La fievre jaune ; rapport de la mission 

 frangaise. Ann. de Inst. Pasteur, tome XVII, November, 1903. 



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