PIROPLASMA MURIS. 515 



IX. EXPLANATION OF PLATE 28, 



Illustrating Mr. H. B. Fantham's paper on "Piroplasma 

 muris, Fant., from the Blood of the White Rat, with 

 Remarks on the Genus Piroplasma.'' 



The figures were all carefully outlined with camera lucida, under Zeiss' 

 3 mm. homog. immersion lens, apert. 1'40, and compensating ocular 18 

 (except in the case of Fig. 23). 



The scheme of colouring adopted is approximately that of Leishman's 

 stain, within the limits of the two colours used, blue and pink. Other 

 modifications of the Romanowsky method used have, for the sake of uni- 

 formity and simplicity, been also thus represented, the tint of the cytoplasm 

 of the erythrocyte only needing to be sometimes modified in sucli cases. 



The magnification is in all cases approximately 1950 diameters, except 

 where otherwise stated. 



Fig. 1. — Pjriform trophozoite, young, with peripheral chromatin and 

 vacuole. 



Fig. 2. — Typical pear-shaped trophozoite. 



Fig. 3. — Ovoid trophozoite. 



Fig. 4. — Pyriform parasite with two chromatic dots. 



Fig. 5. — Trophozoite ("schizont") in process of longitudinal division, with 

 chromatin bodies at the poles and well-marked vacuole. 



Fig. 6. — Typical longitudinal fission of parasite in red blood corpuscle. 



Fig. 7. — Two daughter trophozoites (" merozoites "), bigeminate. 



Fig. 8. — Two pear-shaped parasites, still connected by a thin strand of 

 protoplasm at their pointed ends. 



Fig. 9. — Two ovoid forms, probably resulting from a simple binary fission 

 of the parent parasite. 



Fig. 10. — Two pairs of parasites in a red blood corpuscle, the pairs lying 

 partly over each other. The members of the pairs are still connected, though 

 at different stages of separation. This is probably a case of double infection 

 of the blood-corpuscle host. 



Fig. 11. — Three intra-corpuscular parasites ; possibly a fourth behind the 

 heart-shaped smaller pair. Two chromatin bodies occur in each of the 

 members of the heart-shaped pair. 



VOL. 50, PART 3. NEW SERIES. 37 



