576 HEMOSPORIDIA 



four. Segmentation is generally not seen in the peripheral blood, 

 but it can be shown in blood drawn by puncture from the spleen. 



Examination of Blood. Examination of the blood for the plas- 

 modium of malaria is made on unstained fresh and on dried specimens. 

 The latter are best stained with the Romanowski stain or one of its 

 modifications, such as the Wright stain. 



Hemosporidia in Birds. Birds frequently harbor trypanosomes in 

 their blood, as has been stated previously. Two kinds of hemosporidia 

 have also been found. 



Proteosoma, or Cytosporon danilewsky, or Hemameba relic ta is found 

 in birds of the sparrow family, in predatory birds, pigeons, crows, 

 etc. The life cycle of this hemosporidium is described by Ruge 

 as follows: The youngest parasites are seen in the erythrocytes of 

 birds as a small, round, refractive, sharply defined body, with one 

 minute pigment granule. The young proteosoma is generally situated 

 near one pole of the blood corpuscle, or it may be near its nucleus. 

 The parasite is not motile; it grows rapidly and causes the nucleus 

 of the erythrocyte to move or turn away from it. During growth the 

 pigment increases and becomes lumped together. Afterward the 

 organism breaks up into six to eight merozoites, which are arranged 

 as a rosette or in fan-shape. The largest forms break up into twelve to 

 fifteen spores. The corpuscles infected with the dividing parasites 

 lose their regular shape and burst. The free spores then invade 

 fresh blood corpuscles. Sexually differentiated gametes, however, 

 are also formed in the blood of infected birds. Their further develop- 

 ment occurs in the intermediary host, a mosquito (Culex pipiens). 

 The macrogametes become large and round; the flagellated micro- 

 gametes are formed in a manner resembling the formation which 

 occurs in anopheles in the case of the human malarial plasmodia. 

 The ookinetes are formed in the stomach of the mosquito about 

 twelve hours after it has taken up the infected blood. Seven to ten 

 days later the sickle-shaped sporozoites are found in the salivary 

 glands of the insect. Sporozoite development, however, occurs for 

 a short time only, during temperatures of 24 to 30 C.; between 15 

 to 23 C. their development is much retarded, and at lower temper- 

 atures it ceases entirely. 



Halteridium, or hemoproteus, infects frequently the red blood cor- 

 puscles of predatory birds, singing birds, and particularly pigeons. 

 In tropical and subtropical countries, R. Koch found pigeons very 

 generally infected. Halteridium is generally seen in its typical dumb- 

 bell shape in close apposition with the nucleus of the erythrocyte. 

 The dumb-bell-shaped parasites, according to .Ruge, occur in birds 

 in two types, a hyaline form representing the male, and a finely 

 granular form representing the female element. MacCallum has ob- 

 served how the microgametocytes of the halteridium become flagel- 

 lated and how the microgametes penetrate into the macrogametes. 

 The life cycle of halteridium, however, is not yet completely known. 



