CHAPTER XXXVII 



EXPERIMENTS ON BIRD MALARIA 



By 



Reginald D. Manwell 

 The Johns Hopkins University School of Hygiene and PubHc 



Health 



INTRODUCTION 



Avian malarial parasites are very widespread, and occur in 

 many species of birds. For this reason and because they are easily 

 transferable to canaries by either blood or mosquito inoculation, 

 they offer an attractive field for research. The added fact that 

 there are at least four distinct species offers an opportunity for 

 comparison, and since both the parasites and the diseases they 

 cause bear a close resemblance to the malarial parasites and peri- 

 odic fevers of man the study of the avian malarias becomes genu- 

 inely important, the more especially because no one of the human 

 malarias has as yet been successfully transmitted to any of the 

 lower animals. It is hardly necessary in proof of this statement to 

 point to the results of past work in this field, for the epoch-making 

 discoveries of Ross and MacCallum will instantly come to mind, 

 and the recent development of plasmochin therapy was directly 

 due to long-continued bird experimentation. 



THE PARASITES 



I. Nomenclature and History. That malarial parasites may be 

 found in the blood of birds has been known since 1885, when 

 Danielewski first observed them, and the early investigators be- 

 lieved them identical with those of man. Although Celli and San- 

 Felice described three separate species of malarial parasites as 

 existing in birds, their description was not sufficiently careful to 

 make these species recognizable to-day, and following a zoological 

 study of the parasites published by Labbe in 1894, in which he 



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