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Haughwout: Human Coccidiosis 
467 
and the material on them was literally baked “bone dry.” They 
were then placed in Petri dishes for protection and allowed 
to remain in the same position, still exposed to the morning sun. 
This was on March 18. 
The slides remained thus exposed to the hot sun for about 
three hours each forenoon, until March 25. On that day, an- 
other set of Petri dishes was prepared with wet filter paper in 
the bottom of each, forming a set of moist chambers. The dried 
slides were transferred to these, being supported on match 
sticks and inverted so the water of condensation from the 
filter paper would collect on the faecal film. One or two of the 
slides were mounted in water and examined under the micro- 
scope. Many badly wrinkled oocysts were found, but the contents 
had a healthy, greenish tint. All were in early stages of 
development. 
On the following day (March 26) the slides were examined 
in water mounts, but no changes were noted. On March 27 
one fully developed cyst (Plate 3, fig. 10), not visibly deformed, 
and bearing every evidence of good health save for the unusual 
character of the sporocystic residuum, was found. This cyst 
was firmly embedded at one edge in a mass of fsecal debris, but 
it could be clearly studied. Many cysts found were dead and 
degenerated, but many zygote, sporoblast, and sporocyst stages, 
with badly wrinkled oocysts but with apparently healthy inte- 
riors, were also found. 
The last examination of the slides was made on the afternoon 
of March 29. It was found that there was a tendency for the 
wrinkled oocysts to smooth out. Some of the fully developed 
cysts that appeared to be in good condition, showed a close 
contraction of the oocyst around the sporocysts (Plate 2, fig. 12) . 
The similarity in appearance of the sporocystic residuum to 
that of the cyst just mentioned should be noted. Numbers of 
apparently healthy cysts in intermediate stages of development 
also were found, as well as many, before observed, that clearly 
were dead. 
The experiment, rough as it was, showed that complete des- 
sication of the faeces and daily exposure for at least three hours 
to the tropical sun over a period of a week will not prevent the 
full development of at least a portion of the cysts in a stool, as 
soon as a condition of moisture is restored. How long it would 
take the cysts to develop without the subsequent interposition 
of moisture, I cannot say, but I believe they would develop in 
the course of time. 
