38 
After the slide has been allowed to remain for ten or fifteen min- 
utes in the incubator and is then examined on the warm stage, the 
sporozoites are found to have become actively moving bodies called 
vernficules. By a sort of snakehke or wormlike motion, rapid change 
of place occurred, the red blood corpuscles being vigorously moved 
about when the vermicule came in contact with them. The anterior 
extremity was always the one which had been the broadest and most 
rounded in the sporozoite. In the moving vermicule this extremity 
is more slender and pointed. The entry of vernficules into leucocytes 
was never observed. After two or three hours they became sluggish 
in movement and finally stationary. 
2. AcTIOX of 0.5 PER CEXT SOLUTIOX OF PAXCEEATIC EXTRACT 
IX XOPAIAL SALT soLFTiox. — When sporocysts are exposed to this- 
solution the cysts are rapidly dissolved and the sporozoites set free. 
The latter very soon become contracted into rounded bodies and lose 
all motion. 
3. The digestive .jftces of the mite. — IMites containing sporo- 
cysts were compressed between a shde and cover slip. The chitinous 
envelope was then removed and the cover slip replaced and pressed 
down with sufficient force to rupture the sporocysts and set free the 
sporozoites. The latter, after a short time, performed slow move- 
ments of flexion and extension, and. in addition, some sporozoites 
showed at times a slow gliding motion forward, with intervals of rest. 
When in motion a nfinute point of protoplasm could be seen pro- 
jecting from the anterior end. The protoplasm showed no perceptible 
waves of contraction during tlfis movement. Some of the sporozoites 
at times exhibited slight contractions. Xo movement took place 
inside the unmptured cysts. 
4. Actiox of juice from the duodexum of the eat.— a healthy 
fasting rat was killed, the abdominal cavity opened, and a drop of 
the clear fluid contents of the lower part of the duodenum nfixed on 
a shde with ripe sporocysts. Immediately upon examining with the 
microscope the sporozoites in the unmptured cysts were found to be 
in active motion, moving about with great vigor in the interior of 
the cyst and suggesting very strongly a mass of worms squirming 
over one another. After ten or fifteen nfinutes many cysts were 
seen to mpture and the sporozoites were set free as actively moving 
vernficules. They exhibited all the movements previously described 
as observed when sporozoites were nfixed with rat's blood, except 
that they were intensified. This obseiwation (repeated a number of 
times) upon the action of the intestinal juice upon the sporocysts 
and sporozoites pointed to the intestine as a possible point of entry 
of the infection, in rats, and led to subsequent experiments in this 
direction.- 
