250 
Haemamoebae in Birds 
1. 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. 
