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New Protist Parasites 
the individuals tend to collect in tangled skeins. They never long 
survived removal from the host, and normal salt solution seemed to 
hasten death. In dying there is a strong tendency for the curves to 
become flattened out and more irregular, but I never noticed anything 
that could be described as plasmotypsis. 
On one or two occasions I saw individuals break across, the middle 
portion gradually becoming drawn out “like a glass rod in a flame,” and 
then snapping, but I am unable to say whether this were a true 
transverse division or merely the Anal stage in a longitudinal division. 
I fixed smears with absolute alcohol and stained with Giemsa’s stain, 
but had some difficulty in getting good results. This was probably due 
in part to the obscuring effect of the large amount of bacteria and debris 
in every preparation ; but the spirochaetes themselves did not take on 
the stain easily. Fig. 16 shows typical slender spirochaetes, drawn out 
finely at their extremities and stained an almost uniform pinkish-red 
with Giemsa. The average length is 1 opt, with about 8—6 somewhat 
unequal curves. I saw no hint of an undulating membrane, nor could I 
make out any nuclear structure, though sometimes there appeared to 
be an alternation of slightly lighter and darker areas (Fig. 16a). 
This spirochaete from the larvae of Trichoptera agrees closely with 
that described by Leger (1902) from larvae of Ghironomus, and by Leger 
and Duboscq (1909) from the larva of Ptychoptera contaminata. It 
may very possibly be identical with these, and without further evidence, 
I prefer not to create a new species for it. 
In addition to the spirochaetes in the two larvae just mentioned, the 
only other insect spirochaetes of which I can find record are Spirochaeta 
culicis, Jaffe (1907), from the larva of Culex \ and S. glossinae, Novy and 
Knapp, from Glossina palpalis. 
The record of a new insect host for spirochaetes is therefore not 
uninteresting. 
1 Ed. and Et. Sergent found spirochaetes in the larva of Anopheles maculipennis in 
Algiers ; Patton states that he has found them abundantly in mosquitoes in India; and it 
may also be well to mention in this place the much-disputed Spirochaeta ziemanni, 
Schaudinn, from Culex pipiens. 
