138 C. CLIFFORD DOBELL. 
Fic. 8.—A single spore, more highly magnified. A little cap-like projec- 
tion is seen at one end. 
Fic. 9.—Large, flattened specimen, showing chromidia, and faintly striated 
halo of pink cilia. 
Fic. 10.—Division by constriction. 
Fre. 11.—Subsequent stage in an organism which is about to sporulate. 
The constriction is disappearing, and large chromatin granules are arranging 
themselves in the first stage of a spiral. 
Fic. 12.—A similar stage, probably somewhat earlier—less flattened. 
Fie. 13.—At this stage the chromatin is all arranged in an irregular spiral. 
Fie. 14.—The chromatin is now arranged in two large terminal masses, 
with an irregular intermediate portion. 
- Fie. 15.—A later stage, the intermediate part of spiral breaking up. 
Fie. 16.—Still later. The terminal masses of chromatin are now definitely 
rounded off as the spores. ‘They are stained red. 
Fic. 17.—The spores are now stained a deep blue, owing to the presence 
of a newly-formed spore membrane. 
Fic. 18.—The spores, as their membrane hardens, stain less deeply. They 
have moved away from the extremities, which are seen to be stained blue. 
The intermediate region, however, is now stained pink, owing to the presence 
of the broken up chromidia. 
Fic. 19.—Spores now fully formed; remainder of cell breaking up. 
Fie. 20.—Bacillus spirogyra. (a), Ordinary individual; (4), beginning 
of division; (¢e), organism which has just divided. 
Fic. 21.—Spirillum monospora. (a), Normal individual; (4), indi- 
vidual in which the granules are collected at one end to form a spore; (ce), 
spore now formed, provided with resistant membrane; (@), later stage, 
remains of cell breaking down and leaving the single spore. 
Fic. 22.—Spirocheta bufonis. (a) and (4), two individuals, showing 
general structure. 
Fig. 23.—Treponema-like organism from toad. (a), a thick individual; 
(0), a very slender one. In (c) a tapering process (? flagellum) is seen at one 
end. 
