234 GilriitJi, Siveet, and Dodd : 



5. The host-cell is more markedly pyriform, and the nucleus 

 much displaced. The parasite has a spherical pinkish finely 

 granular body with no defined nucleus and coarse granules 

 scattered throughout (cf. Fig. 3. Fig. 13 is similar, but shows 

 a slightly defined, small, eccentric nucleus in the parasite, which 

 occupies a more oval host^cell). 



2.— Haemogregarina megalocystis, n. sp. 



(Plate XXIX., Figs. 1-12). 

 Host animal Python spdotes, var. variegata. 



As will be seen this reptilian parasite is to be regarded as 

 belonging to the genus Haetnogreyarina (s.s.) (cf. Doflein p. 

 681-2) rather than Karyolysus since the atrophied nucleus 

 associated with the presence of the latter is absent here, al- 

 though a degeneration of the stroma of the host erythrocyte is 

 present somewhat comparable to that found in the case of 

 Karyolysus lacertarum. 



The blood smears taken from this host showed very many of 

 the red blood corpuscles to be affected with haemogregarines, 

 two or three in one " field " not being uncommonly seen, while 

 in one chance " field " 1.1 mm. in diameter, 10 such infected 

 erythrocytes were counted to about 600 normal corpuscles. 



The infected host-cells are always enlarged, being generally 

 two to three times the normal size, though so far as we could 

 find not more than one parasite is present in each. The 

 cytoplasm of the host-cell is extremely tenuous, and in the 

 larger forms is completely dehaemoglobinised, so much so that 

 when overlapping another corpuscle little or no obscuration 

 can be detected. In the less enlarged host-cells, the dehaemo 

 globinisation is proportionately less noticeable, the staining 

 in the former case showing veiy faintly pui-ple, against the dis- 

 tinct red of the normal erythrocyte. The nucleus of the host-cell 

 is distinct often displaced towards one extremity, or to one side, 

 and rarely lying on the convex borders of the parasite. The 

 influence of the parasite on the host-nucleus is seen not in 

 atrophy, but in its longer, and rarely narrower, sometimes 

 wider outline, while it stains much more deeply and more 



