11 
1920.] Dore.—Some Avian Haematozoa in New Zealand. 
It will be seen from the above tables that the parasites cause very 
little alteration to the erythrocytes. The number of birds infected with 
this parasite in this district totals approximately 5 per cent. The nuclei 
of the host cells were in some cases slightly displaced. 
Description of Six Successive Parasites. — (1.) Protoplasm pale blue; 
nucleus appears as three fine strands, central in position, and pinkish in 
colour ; six granules of melanin towards one end and four towards the 
other. 
(2.) Protoplasm very pale blue ; nucleus pale pink, spherical, central 
in position, spans the breadth of the parasite ; sixteen granules of melanin, 
scattered. 
(3.) Protoplasm practically unstained ; nucleus pale pink, oval, and 
central in position ; five granules of melanin at each end. 
(4.) Protoplasm deep blue ; nucleus spherical, very minute, central in 
position ; three granules of melanin towards one end and nine lying around 
the nucleus. 
(5.) Protoplasm very pale blue ; nucleus purple ; measures two-thirds 
the length of the parasite, and situated to one side, as a strand almost 
touching the nucleus of the erythrocyte ; four granules of melanin at each 
end. 
(6.) Protoplasm deep blue, granular ; nucleus very small, rod-shaped, 
central in position, pale pink ; one small mass of melanin at one end only. 
Plasmodium of the Song-thrush ( Turdus musicus). 
The infected birds were shot in the Waikato district. Blood-films were 
prepared from the heart, fixed in absolute alcohol, and stained by the 
Giemsa method. 
The Parasites stained. —The parasites appear as rounded or irregularly 
shaped oval bodies, usually situated at the distal end of the erythrocyte, 
the nuclei of which were generally displaced, except in the case of a young 
parasite recently invading the cell. 
The displacement of the nucleus is usually parallel to the long axis of 
the erythrocyte. Sometimes two parasites are seen in a cell, one on each 
side of the nucleus : under these conditions the nucleus remains central 
in position, but the erythrocyte shows slight distortion. The nuclei of the 
parasites were very inconsistent in size, shape, and staining, sometimes 
appearing as small compact masses staining purple, or at other times 
merely as thin rods. 
Melanin was present in small masses, lying usually at the sides of the 
parasites. The erythrocytes were partly dehaemoglobinized, and there¬ 
fore stained badly. All stages of the schizogenic cycle of the parasites 
were present in the blood of some of the infected birds. The youngest 
forms, which measured 1*6 /x, appeared as minute masses of protoplasm 
containing a chromatin granule but devoid of melanin. Multiple infection 
was common, and occasionally as ^any as six parasites were observed in 
an erythrocyte. Male and female gametocytes were observed. A count 
of 200 consecutive parasites showed the following percentages • Male 
gametocytes, 40 per cent. ; female gametocytes, 50 per cent. ; doubtful 
forms, 10 per cent. 
Segmenting forms were observed in 4 per cent, of the infected erythro¬ 
cytes. The rosettes, which occupied one-third of the host cell, consisted 
of 14 to 16 merozoites. In the centre of these rosettes a mass of pigment 
was usually present. The merozoites were often observed in the vicinity 
of disintegrated erythrocytes, the remains of which stained poorly. The 
