NOTES ON SOME PARASITIC. PROTISTS. oe 
single terminal mass of nuclear granules in the spore form- 
ation of Sp. monospora. 
Spirillum monospora remains actively motile until the 
spore is fully formed. It then presents a very characteristic 
appearance, as it swims about bearing its glistening, terminal 
spore. 
IV. Spirocheta bufonis, n.sp. (PI. 6, figs. 22a, b.) 
I have little to say regarding this organism beyond record- 
ing its presence. It is very rare, so far as my experience 
goes. I have found it but once, in the rectum of Bufo 
vulgaris, L., and then in only very small numbers. It 
measures about 8—10y in length by about 1°5 py in breadth. 
There are very few turns to the spiral, which displays some 
irregularities owing to the flexibility of the organism. The 
average distance between the turns is about 3. 
An undulating membrane or periplastic sheath can usually 
be seen extending from one end to the other. ‘The spirocheet 
resembles ‘8. buccalis, Cohn., but I have never seen terminal 
flagella, which are described in this species. The organism 
is very actively motile. 
No internal structure has been satisfactorily demonstrated. 
A granular appearance of the protoplasm is usually to be 
seen, somewhat resembling that figured by Jaffé in §. culicis 
—another gut-inhabiting spirochet, from Culex larve. 
V. Treponema (?), sp. (PI. 6, fig. 23a, b, c, d.) 
An organism which appears to belong to the genus 
Treponema, Schaud., has been found by me on two occa- 
sions in the large intestine of the toad, B. vulgaris, L. 
Both animals were captured in the same locality, and con- 
tained the parasite in large numbers. 
This organism is more difficult to observe in the living 
state than any other which I have ever encountered. It is 
