250 



HAEMAMOEBAE IN BIRDS 



I. H. relicta (Proteosoma grassii). Discovered 

 by Grassi in the blood of birds in Italy. It causes 

 a fatal disease in the Hungarian partridge (Perdix 

 cinerea). In certain regions sparrows and goldfinches 

 are commonly infected. Sparrows are frequently 

 infected in India. In Africa numerous small birds 

 were examined by us, but Proteosoma was never 

 found (only Halteridium). Transmission from one 

 bird to another by inoculation is readily effected. 

 Canaries are extremely susceptible. Pigeons, among 

 other birds, are immune. Birds that have recovered 

 from an infection have acquired a well-marked 

 immunity against a subsequent inoculation. The 

 parasite,- is closely allied to the malaria parasite, and is 

 especially suitable for the study of the exogenous 

 mosquito cycle. 



Endogenous Cycle (Fig. 75). The parasite in its 

 earliest stage is unpigmented. Coincident with 

 growth a grain or two of pigment appears, and the 

 characteristic property of the parasite shows itself, 

 viz., the displacement of the nucleus of the red cell, 

 so that the nucleus may take up a position at right 

 angles and away from the normal one. All stages of 

 development up to segmenting forms are found in the 

 blood at the same time, so that no cycle of development 

 can here be followed ; nor is there any intermission 

 in the clinical symptoms (temperature, etc.) of infected 

 birds. 



Exogenous Cycle. Besides the asexual, sexual 

 forms occur in the blood. They are spherical hyaline 

 bodies of two varieties, characterised in stained 

 specimens by the-- same general differences which 

 distinguish the male and female gametes of the 

 malaria parasite. 



