R. Kudo 
237 
C. protei, but differ from the latter forms. Ohlmacher’s view is untenable 
because myxosporidian spores have no power of locomotion and have never 
been seen or been made to germinate in water outside of the host. 
As previously stated, a series of experiments was carried out to discover 
the way in which infection occurs. An emulsion of fresh spores in physiological 
solution was prepared. Small pieces of a sterilized cork, made porous by means 
of a fine needle, were immersed in the emulsion, and introduced into the oeso¬ 
phagus of several specimens of R. pipiens. Small pieces of infected kidneys 
were also fed in a similar manner. At various intervals of time, the animals 
were dissected. The cork was found in the pylorus even after 48 hours, and 
in two cases it was seen to have reached the large intestine. The corks, after 
being taken out, were cut into smaller pieces on many slides and studied. 
Four intestines with the introduced corks were fixed and sectioned. 
Hanging drop preparations were made by mixing fresh spores with the 
fluids taken from various parts of the digestive tract. Further changes than 
the extrusion of polar filaments and occasional separation of the shell-valves 
were noticed only in the preparations with the gastric fluid with or without 
bile or fluid from the duodenum. In these preparations which have been 
absolutely free from mechanical pressure, the amoebulae were frequently 
noticed making their way through the opening of the spore membrane. Similar 
changes were noticed in the smears of corks taken from the pylorus. From these 
experiments, we may conclude that the amoebula emerges in the pylorus or 
duodenum of the new host. 
It may seem probable that the liberated amoebulae pass through the 
alimentary canal into the cloaca where the ureters open, as was thought by 
Davis in S. dimorpha, and make their way up the ureters and further into the 
uriniferous tubule of the kidney. However, this supposition does not seem to 
hold, as the young stages only occur in or near the Malpighian bodies. 
I therefore concur with Joseph's opinion that the liberated amoebulae 
penetrate through the wall of the digestive tract, appear in the coelomic 
fluid, and finally reach the nephrostome through which they further make 
their way into the lumen of the uriniferous tubule of the host’s kidney. 
Judging from the conditions observed in sections of infected kidney, this 
seems to be the most common way for amoebulae to reach their final seat 
of infection. Frequently the space between Bowman’s capsule and the glo¬ 
merulus of the Malpighian body is greatly enlarged, and filled with young as 
well as sporulating trophozoites, while the uriniferous tubule originating from 
this body, contains no parasites. This may be due to the amoebulae which 
have entered the blood stream and which, after reaching the capillary in the 
glomerulus, have traversed its wall and become free in the said space where 
active multiplication takes place. 
The mature spores pass down the uriniferous tubules and ureters, and 
escape outward through the anus. When they are swallowed by a new host, 
the fresh infection follows. 
Parasitology xiv 
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