PLATE I. 
Taken from ‘* Monthly Microscopical Journal,’’ of Sept. 1st, 1875. 
Fie 1. —a. B. termo magnified with the same power as b, which 
is a specimen of Spirillum volutans, showing flagella at each end. 
Fic. 2. — B. termo, as seen with a power of about 600 diameters. 
Fic. 3. — The same as seen with 3; and second eye-piece (3,700 
diameters). 
Fic. 4. — B. termo, seen with flagellum at one end, the light com- 
ing in the direction of the arrow. 
Fie. 5. — The same object when it moved at right angles to its 
former position, the light coming from the same direction, causing 
the sight of the flagellum to be lost. 
Fic. 6 represents one B. termo which was in a still condition, 
but one flagellum moving. The light came in the direction of the 
arrow. When the end marked 2 } was in focus, a flagellum was 
seen, but none at the endc. When the end marked 1 a was fo- 
cused carefully, the flagellum at that end was seen, aud lost at the 
end d. 
Fie. 7. — The true form of B. termo. 
Fig. 8. — The form as shown by the ‘‘ supplementary stage ”’ il- 
lumination before flagella were found, showing the pointed ter- 
mination of the body at a, b. 
