THE HAEMATOZOA OF AUSTRALIAN BIRDS. 421 



in any particular film were usually of one or other of these 

 types, in some films both forms were present as well as 

 others of intermediate size. 



The intracorpuscular forms were more or less globular, 

 ami lay in the protoplasm of the host-cell, embayed in the 

 nucleus which sometimes surrounded the parasite so as to 

 envelop three-fourths of its circumference. The bodies 

 were usually deeply stained blue, but occasional much 

 paler forms were seen. As already stated they possessed a 

 central macronucleus, and occasionally, near the periphery, 

 what appeared to be a micronucleus was present. 



Considerable doubt existed for a long time as to the 

 nature of the host-cell. Though the tinting of its nucleus 

 was similar to that of an injured red cell (having the same 

 reddish colour), irregular corona-like projections on the 

 far side of the host-nucleus suggested that the cell might 

 be a leucocyte. The question was, however, finally set at 

 rest by detecting, in a film from Ptilotis fusca, very early 

 intracorpuscular forms, without question parasitizing red 

 cells. In one the protoplasm of the red-cell was still quite 

 distinct, and its nucleus was being indented by the parasite 

 so as to form a kind of cap to it. Of course it is not 

 impossible that mononuclear leucocytes may also act as 

 host-cells. 



It is of much interest to note that our intracorpuscular 

 trypanosomes (or 'leucocytozoa'), while distorting the 

 nucleus of the host-cell by indentation and stretching, in 

 no instance cause the extraordinary elongation of host-cell 

 and nucleus seen in Leucocytozoon zlemannL This alone 

 shows that the species are distinct. 



We think it highly probable that the trypanosomes and 

 intracorpuscular bodies we have found in several Australian 

 birds are all referable to the same species, and this we have 

 already designated as Tryp. anellobiae. It will be seen 



