1910.] NATURAL SCIENCES OF PHILADELPHIA. 39 



Fig. 23. — Camera outline. Wright's stain. Mouse L26, 3 to '-<\ hours. Early 

 male form. The cytoplasm has nearly disappeared. The nucleus is typical. 



Fig. 24. — Camera outline. Mouse L26, 3 to 3^ hours. Early male stage. 

 Cytoplasm greatly reduced. Nucleus very large with a well-developed 



nuclear iii -I , 

 Fig. 2"). — Camera outline. Iron hematoxylin. Mouse 261, I hours/ int. —'■'>. 



Early stage of doubtful sex. Cytoplasm sharply delimited and dense. 

 Nuclear net obscured. A large black granule present. 



Fig. 26. Camera outline. Iron hematoxylin . Mouse 2fd , 4 hours, int. —3. 

 Parasite lies in what seems to be a mucous cell. Cytoplasm dense and 

 nearly homogeneous. Nucleus clear cut, showing a sharply marked karyo- 

 some and two conspicuous black granules. This parasite might be either 

 a male or a female. 



Fig. 27. — Camera outline. Thionin. Mouse 261, -4 hours, int. —3. Early male 

 stage. Consists of an enlarged nucleus surrounded by a narrow strip of 

 cytoplasm, with a quantity of degenerate material lying on one side. The 

 parasite is probably cut obliquely. The nuclear net is well developed. 



Fig. 28. — Free-hand drawing. Thionin and acid fuchsin. Mouse 247, 4 hours, 

 int. 14. Early female stage. Cell outlines smooth and cytoplasm appar- 

 ently not degenerate. Nucleus rather small with a clear-cut membrane 

 and a central karyosome. 



Fig. 29. — Camera outline. Iron hematoxylin and acid fuchsin. Mouse 247, 



4 hours, int. 14. Early female stage. Cell boundaries sharp. The 

 cytoplasm is neither degenerate nor has it suffered any loss in quantity. 

 The nucleus does not cause any protrusion of the sides of the cell. A large, 

 distinct karyosome is present. Figure diagrammatic. 



Fig. 30. — Camera outline. Delafield and acid fuchsin. Mouse 247, 4 hours, 

 int. 19. Form difficult to classify. The cytoplasm shows a distinct external 

 boundary and, while vacuolated, is apparently not degenerate. Nucleus 

 is a vesicle with a very large central mass. 



Fig. 31. — Camera outline. Iron hematoxylin and acid fuchsin. Mouse 250, 



5 hours, int. 22. Male. Cytoplasm has disappeared, except for a cres- 

 centic mass at one end. The nucleus is greatly enlarged and shows a well- 

 developed net. The net itself is acidophil, the granules associated with it 

 are basophil. 



Fig. 32. — Camera outline. Iron hematoxylin and acid fuchsin. Mouse 250, 

 5 hours, int. 22. Male. Cytoplasm has apparently wholly disappeared. 

 The nucleus is very large and shows an acidophil net beset with a number 

 of sharply basophil granules. 



Fig. 33. — Camera outline. Iron hematoxylin and acid fuchsin. Mouse 250, 



5 hours, int. 22. Female. Cytoplasm dense and, while vacuolated, shows 

 no signs of degeneration. Nucleus a vesicle with a large karyosome and 

 two intensely black granules. Strands joining the karyosome with the 

 nuclear membrane could not be made out. 



Fig. 34. — Camera outline. Iron hematoxylin and acid fuchsin. Mouse 250, 

 4 hours, int. 22. Female. Cytoplasm shows no signs of degeneracy. It 

 consists of a lighter ground substance in which are a number of poorly 

 defined darker bodies. Nucleus a vesicle in which is a large karyosome. 

 Little strands extend out from the karyosome, but they could not be traced 

 the whole distance to the nuclear membrane. Two black granules present. 



Fig. 35. — Camera outline. Delafield and acid fuchsin. Mouse 253, 6 hours, 

 int. 19. Female. In this figure an attempt is made to indicate the alveolar 

 character of the cytoplasm of the females. Nucleus a vesicle containing a 

 large karyosome. 



Fig. 36. — Camera outline. Delafield and acid fuchsin. Mouse 253, 6 hours, 

 int. 19. Female. Cytoplasm rather dense, but liberally vacuolated. 

 Nucleus a vesicle with a large karyosome. 



Plate III. — Fig. 37. — Camera outline. Delafield and acid fuchsin. Mouse 253, 



6 hours, int. 19. The figure shows two females which have invaded the 

 same cell and developed side by side. 



1 See the annotation with regard to mouse 261, on p. 19. 



