16 PORTER. 
EXPLANATION OF PLATE I. 
Fic. 1. Cross section of Clymenella torquata, showing sections of eighteen 
gregarine cysts. X 40. 
cys, cysts before the beginning of spore formation. 
Fic. 2. Mature living cyst illuminated from above. X 136. 
Fic. 3. Conjugating gregarines drawn from a living specimen. X 136. 
Fic. 4. Gregarine just after encystment, drawn from living specimen. X 136. 
Fic. 5. Early stage in spore formation, drawn from parasite. X 136. 
Fic. 6. Section of a gregarine showing the breaking up of the nucleus before 
encystment. X 350. 
cav, cavity caused by the shrinking of the protoplasm away from the sur- 
rounding tissue of the host. 
prpl, granular protoplasm. 
pr’pl,” frothy or vacuolated protoplasm. 
Fic. 7. Section of gregarine, imbedded in tissue of host, after disappearance 
of nucleus and before the beginning of sporulation. X 350. 
a, 8, y, 5, spaces occupied by other cysts. 
Fic. 8. A portion of the central mass of protoplasm shown in Fig. 9 highly 
magnified. X 3100. -— 
Fic. 9. Section of a cyst showing the formation of sporogonia and the con- 
dition of the central mass of protoplasm. X 350. 
Fic. 10. Another section of the same cyst. X 350. 
Fic. 11. Portion of the same cyst more highly magnified, showing structure of 
recently formed sporogonia, their manner of formation, and the condition of the 
protoplasm. X 1540. 
rtl, protoplasmic network. 
Fic. 12. Section of cyst in a later stage of the formation of sporogonia. X 
230. 
cys, wall of cyst. 
a, former position of wall of cyst, determined by surrounding tissue of host. 
vil, fine filamentous network. 
Fic. 13. Part of central mass of protoplasm, shown in Fig. 12, more highly 
magnified. X I100. 
spo’go, recently formed sporogonia. 
spo’go,, sporogonia not yet fully formed. 
chr, mass of chromatin granules. 
Fic. 14. Sporogonia from same cyst. X 3100. 
Fic. 15. Section of cyst when spore formation is almost completed. X 400. 
pr pl, protoplasm not yet converted into sporogonia. 
spo’go, sporogonia with eight nuclei. 
spo’go,’ a sporogonium after the first division of the nucleus. 
mb, exceedingly thin transparent membrane. 
