LIFE-CYCLE OF " CYSTOBIA " IRREGULARIS (mINCH.). 99 



Fig. 44.— Varying character of the encystmeat process in "Cystobia"; 

 tf is a section of C. minchinii, the rest being of C. irregularis (for 

 description see text). (iV. Nuclei of inner epithelial layer and of connective- 

 tissue layers.) Iron.-lifem. + orange or eosin (except e, which is thionin + 

 orange). All X 850. 



PLATE 5. 



Nuclear changes and multiplication. (All figures are from sections, and all 

 relate to C. irregularis, except fig. 55, which is of C. minchinii.) 



Pig. 45. — Commencing nuclear changes : b. is the other nucleus of the 

 parasite. Corr. subl. + acetic, Klein, hsem. -j- eosin. x 300. 



Fig. 46. — Two nuclei of the 8-uuclear stage. Iron-hsem. + orange. 

 X 1150. 



Fig. 47. — («) and {b) Daughter nuclei of the ;4th generation ; {c) one 

 of the third generation dividing. Corr. subl. -f acetic, iron-hsem. -f orange. 

 X 850. 



Fig. 48. — Stages in fragmentation of the daughter-karyosomes. All nuclei 

 of the fourth generation. Corr. subl. + acetic, iron hsem. + orange, x 700. 



Figs. 49 and 50. — Commencing distinction of the multiplying nuclei into 

 large sterile ones and small germinal ones. 



(49) Thionin + orange \ . 



,rn\ T 1 1 • V after corr. subl. + acetic. X 850. 



(50) Iron-hsem. -f- eosin ) ' 



Fig. 51. — Later stage, a. b. Resting sexual nuclei, c.-f. Dividing ones. 

 (/.—j. Centrosomic division. Tc. Sterile nucleus. (The arrows point to 

 figures constructed from two or three sections.) x 850. 



Fig. 52. — Stages in the disintegration of tiie large sterile nuclei. Flemming, 

 iron-hspm. -\- orange, x 850. 



Fig. 53. — («) Equal distribution of the nuclei and commencing segregation 

 of the cytoplasm into sporoblasts. X 175. (b) Part of periphery of similar 

 cyst. Cytoplasm loose and lull of chromntoid granules. Both corr. subl. + 

 acetic, iron-hsem. + orange. X 850. 



Fig. 54. — Cyst containing zygotes or copuiae, about stage c-d, fig. 58. No 

 cystal residue. Corr. subl. + acetic, para-carmine. X 175. 



Fig. 55. — Earlier stage in C. minchinii, showing the intertwining pro- 

 cesses. (The connective tissue, etc., surrounding the cyst is not shown [see 

 fig. 44 (?.]). Corr. subl. + acetic, thionin + orange. X 175. 



Fig. 56. — Corresponding stage in C. irregularis. Owing to the sporo- 

 blast nuclei («) being less numerous and less closely arranged, the outlines of 

 the segments are not quite so sharply defined. Corr. subl. + acetic, thionin 

 -\- orange. X 175. 



