PLATE I. 



Taken from " Monthly Microscopical Journal" of Sept. 1st, 1875. 



Fig 1. — a. B. termo magnified with the same power as 6, which 

 is a specimen of Spirillum volutans, showing flagella at each end. 



Fig. 2. — B. termo, as seen with a power of about 600 diameters. 



Fig. 3. — The same as seen with ■£$ and second eye-piece (3,700 

 diameters). 



Fig. 4. — B. termo, seen with flagellum at one end, the light com- 

 ing in the direction of the arrow. 



Fig. 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. 



Fig. 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 b was in focus, a flagellum was 

 seen, but none at the end c. When the end marked 1 a was fo- 

 cused carefully, the flagellum at that end was seen, and lost at the 

 end d. 



Fig. 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. 



