Parasites of Frogs and Toads. 
433 
covering the sporogony of this organism. Examination of the 
intestine, liver, and kidneys for stages in schizogony has had only 
negative results. The Coccidium resembles G. salamandrae 
Steinhaus, somewhat. There is a large oocystic residuum, each 
spore also containing a large sporoplasmic remainder. The spores 
are fusiform, and resemble those of Monocystis (which often pass 
through the frog’s intestine) but differ, of course, in containing 
only two sporozoites. I have followed the development of the 
uninucleate oocyst up to the completion of the formation of 
sporozoites in the living animal, but have not been able to obtain 
stained preparations, owing to the extraordinary impermeability 
of both the oocysts and spores. 
The sporozoites probably leave the spores in the upper part 
of the small intestine of their new host. 
In conclusion, I may mention that I have observed — I believe 
for the first time — the cysts of Nyctotherus cordiformis Ehrbg. 
They are oval, of a greenish-yellow colour, and display a striation 
which follows the lines of cilia on the creature. Their length is 
about 80 — 90yit. The cytopharynx, nucleus, &c. remain unchanged 
inside the cyst. These cysts are probably the means by which 
infection of new hosts is brought about. 
