THE PARASITE MINCHINIA. 457 



Fig. 3. Portion of a section of an encysted parasite beginning' to break up into 

 gametes : c, cyst with host-cells flattened against it ; ff., amoeboid gamete. 

 Stained EhvHch's hematoxylin. X 2000. 



4. Portion of a cyst containing free and conjugating gametes. X 3000. 



5. ((?) Prozygote formed by fusion of the cytoplasm of two gametes. Stained 



Ehrlich's hasmatoxylin. (6) Zygote showing formation of syncarvon. 

 (c) Zygote with syncaiyon. All X 3000. 



6. Zygote showing first division of the syncaryon. X 3000. 



7. Later stage : second division nearly complete. X 3000. 



Plate II. 



Fig. 8. Portion of a cyst showing two stages of division into the four sporoblasts : 

 s., free sporobla>ts. X 3000. 

 9. Stages in early spore-formation from sections. X 3000. (a) Showing be- 

 ginning of nuclear activity ; (6) showing single parietal nucleus ; 

 (c) showing two such bodies and a portion of the membranous coat and 

 tail cut through. 



10. Young living spore from a cyst : the clearer space indicating position of 



nucleus. X 2000. 



11. Slightly older spore also drawn from the living. X 2000. 



12. Young spore with lai-ge nucleus giving off chromatic bodies into cytoplasm. 



X 30U0. 



13. Optical section of a spore nearly full grown and with chitinous coat (cJi.) 



almost complete. Membranous tails {t.) cut through spherule (sjo.). 

 X 3000. 



14. Optical section of a free spore at stage between those represented by figs. 12 



and 13, showing chromatic grannies arranging themselves just inside 

 membrane to form chitinous coat. Slightly flattened by cover-glass. 

 X 2000. 



15. Adult spore drawn from the living. X 1000. 



16. Spore opened by means of pressure and reagents. X lOUO. 



