Report on the Bacteriology of Water. 

 FIG. 15. 



285 



evening, and by 10 P.M., or thereabouts, was completed in all respects 

 as a ripe spore like that started with sixty-nine hours previously. 



A still better series of stages observed in the development of the 

 spore is shown in fig. 18. The filaments of a very vigorous culture 

 in broth at 20 C. were passing over to the development of spores in 

 nineteen to twenty hours after sowing, and at 10.55 A.M. the cells, 

 about twice as long as broad, had their protoplasm studded with the 

 minute brilliant points already referred to (fig. 18 a). These bright 

 masses stain deeply with methylene blue, as said, and are prob- 

 ably of the nature of the chromatin granules referred to in works on 

 bacteriology.* They also slowly change their positions in the pro- 

 toplasm, and at 11.40 A.M. had changed in numbers, positions, and 

 sizes, as shown in fig. 18 6. These changes slowly proceeded, in the 

 case under observation, until all the bright substance was aggre- 

 gated near the centre of the protoplasm into a more or less definite 

 oval body (tig. 18 c) which is evidently the incipient spore. This 

 was at 9 P.M. During the night these masses had each become 

 larger, more defined, and had clothed itself with a distinct cell wall 

 (fig. 18 d). Each cell now contained one distinct oval spore, 

 and was more cut off from its neighbour by a tendency to rounding 



* See Hueppe, ' Methoden,' loc. cit. 



