38 PROCEEDINGS OF THE ACADEMY OF [Jan., 



Fig. 7.— Camera outline. Delafield. Mouse 248, 2 hours, int. 15. Typical 

 early male form. Nucleus greatly enlarged; cytoplasm reduced to two 

 separate masses, one at each end of the parasite. Nuclear net distinct. 



Fig. 8. — Camera outline. Thionin and acid fuchsin. Mouse 248, 2 hours, 

 int. 30. Early male stage. Cytoplasm beginning to show irregular out- 

 lines and to become vacuolated. Nucleus not greatly enlarged, but otherwise 

 typical. 



Fig. 9. — Camera out line. Thionin and acid fuchsin. Mouse 248, 2 hours, int. 30. 

 Early male stage. Shows very clearly the degeneration of the cytoplasm, 

 evidenced by the rough outlines and vacuolization. Nucleus enlarged, with 

 a distinct nuclear net. 



Fig. 10.— Camera outline. Thionin and acid fuchsin. Mouse 248, 2 hours, int. 30. 

 Early male stage. Cytoplasm degenerate. Nucleus elongated transversely, 

 a frequent appearance in the early stages. Nuclear net showing a single 

 large central mass, in which is a vacuity. 



Fig. 11. — Camera outline. Thionin and acid fuchsin. Mouse 248, 2 hours, 

 int. 30. Early stage of male. Cytoplasm reduced in amount and degenerate 

 in appearance. Nucleus greatly enlarged with a central aggregation differen- 

 tiated into an acidophil mass beset with basophil granules. 



Fig. 12. — Free-hand drawing. Thionin and eosin. Mouse 248, 2 hours, int. 30. 

 Early male. Shows a method of degeneration of the cytoplasm frequently 

 observed. The cytoplasm consists of a number of basophil masses lying 

 in a faintly staining matrix. The nucleus was typical. 



Fig. 13. — Free-hand drawing. Thionin and eosin. Mouse 248, 2 hours, int. 30. 

 Early male stage. Shows mode of degeneration of cytoplasm, which at one 

 end of the parasite is broken up into a mass of basophil lumps, apparently 

 lying free in the host tissue. The nucleus was typical. 



Fig. 14. — Camera outline. Thionin and eosin. Mouse 248, 2 hours, int. 30. 

 Early male stage, probably slightly earlier than the form shown in fig. 13. 

 The cytoplasm has separated into a number of denser masses, taking the 

 thionin, which lie in an almost achromatic ground substance. The nucleus 

 is typical. 



Fig. 15. — Camera outline. Wright's stain. Mouse 125, 2 to 2§ hours. Early 

 male stage, showing nuclear enlargement. 



Fig. 16. — Camera outline. Wright's stain and eosin. Mouse 125, 2 to 2\ hours. 

 Early male stage. 



Plate II. — Fig. 17. — Camera outline. Wright's stain and eosin. Mouse 125, 



2 to 2\ hours. Early male stage. Cytoplasm greatly reduced and degener- 

 ate. Nucleus much enlarged with a very distinct nuclear net. 



Fig. 18. — Camera outline. Thionin and acid fuchsin. Mouse 249, 3 hours, 

 int. 22. Two early males, both lying in the same vacuole. In both the 

 nuclei are enlarged, and although the cytoplasm is reduced, it still retains 

 its smooth outlines and is not vacuolated. Nuclei typical. 



Fig. 19. — Camera outline. Thionin and acid fuchsin. Mouse 249, 3 hours, 

 int. 22. Male. Cytoplasm reduced to a small cap at either end of the 

 parasite. Nucleus greatly enlarged and showing the usual structure. 



P'ig. 20. — Camera outline. Iron hsematoxylin and acid fuchsin. Mouse 249, 



3 hours, int. 30. Early male stage. Cytoplasm somewhat reduced in quan- 

 tity and showing signs of degeneration. Nucleus shows a net of the usual 

 character and is provided with one large conspicuous granule. This kind 

 of granule appears to require iron hsematoxylin for its demonstration. The 

 parasite lies in a partly emptied mucous cell. 



Fig. 21. — Camera outline. Iron hsematoxylin and acid fuchsin. Mouse 249, 

 3 hours, int. 30. Possibly an early female stage. Cytoplasm dense; 

 nucleus clear cut with a central mass and three black granules on periphery. 



Fig. 22. — Camera outline. Thionin and acid fuchsin. Mouse 249, 3 hours, 

 int. 22. Probably an early female stage. Cytoplasm sharply delimited 

 and dense. Nucleus enlarged, but not sufficiently so as to cause bulging of 

 the cell boundaries. Within the nucleus is a round red body from which 

 blue rays extend to the nuclear membrane. 



