196 BIRD MALARIA [CH. 



In the first place the disease has been definitely proved to 

 be non-contagious, but is infectious in the same way as yellow 

 fever and malaria. Secondly, the distribution of dengue more 

 or less coincides with that of Culex fatigans. Additional 

 support, however, is that brought forward by E. H. Ross, 

 who shewed that in Port Said, Egypt, dengue entirely dis- 

 appeared after the destruction of mosquitoes. Previously the 

 town had been subject to severe epidemics, but since the 

 extermination of the mosquitoes, not a single case of dengue 

 has been recorded, although the disease has been rife in other 

 parts of Egypt. 



Of course, it is possible that other Culicines may be capable 

 of transmitting the infection, and the observations of Legendre 

 in Hanoi suggest that Stegomyia is probably a carrier of the 

 virus. 



REFERENCES. 



Ashburn and Craig (1907). Experimental investigations regarding the 



etiology of Dengue Fever. Philippine Jour. Sci. Sect. B, Med. Sci. 



vol. ii. No. 2. 

 Graham (1903). The Dengue ; a study of the pathology and mode 



of propagation. Journ. Trop. Med. 1903, p. 209. 

 Legendre (1911). Bull. Soc. Path. Exot. vol. iv. p. 26. 

 Seidelin, H. (1913). Dengue. A summary. Yellow Fever Bulletin, 



vol. n. pp. 335-358. (Contains a very good general account of the 



disease.) 



III. BIRD MALARIA (Plasmodium prcecox [Grassi and Feletti]). 



General account. A great variety of birds, such as finches, 

 sparrows, crows, etc., have been found infected with a parasite 

 closely resembling the Plasmodia of man. By some authors 

 this bird parasite has been separated off into a distinct genus, 

 Proteosoma, but the differences between it and Plasmodium are 

 so slight that now the two are generally united. There is also 

 some doubt as to whether all the Plasmodia occurring in birds 

 should be regarded as one species, and some observers have 

 preferred to give specific names to the Plasmodia from different 



