Report on the Bacteriology of Water. 273 



second of his three sab-families the Baculogence though it is some- 

 what difficult to accept his statement that the bacillar segment, and 

 not the filament, is the primary form. Be this as it may, however, 

 this Thames schizomycete must be excluded from the Trichogence, 

 Saccardo's first sub-family, embracing the genera Crenothrix, Clado- 

 thrix, Beggiatoa, and their allies, as well as from his third group 

 the Coccogence which includes Micrococcus, Sarcina, Streptococcus, 

 <fec., &c. 



Among the Baculogence which includes the genera Bacillus, Clos- 

 tridium, Vibrio, Bacterium, and their allies it clearly comes under 

 the Endosporece, a group embracing those genera which produce 

 definite spores in the rods Pasteuria, Thiodictyon, Hantegazzia, 

 Bacillus, Pasteurella, Clostridium, Cornilia, Vibrio, Spirillum, and 

 Spiromonas. 



Pasteuria is excluded by its mode of longitudinal division. Thio- 

 dictyon by its ccenobial colonies. Spirillum and Spiromonas by their 

 regular corkscrew-like twisting. Cornilia and Vibrio by their pecu- 

 liar spore-formation and other characters ; whence we are reduced to 

 the true bacillese (JEubacillece). 



This sub-group includes the genera Mantegazzia, with fusiform 

 rodlets ; Bacillus, with cylindrical rodlets ; and Pasteurella and 

 Clostridium, each of which has peculiarities of spore-formation 

 different from those described. 



This brings us to the genus Bacillus proper. 



The further subdivision of this genus is still very unsatisfactory. 

 Saccardo adopts a series of sections based on the habitats, whether 

 anthrophobic, zoobic, pyogeuic, zymogenic, saprophytic, and endo- 

 phytic, subdividing further, according to the organs the pathogenic 

 forms occur in, the behaviour towards gelatine, whether they form 

 pigments, and so on. 



Accepting this provisionally, the species in question comes under 

 the saprophytic section. Here we find forms peculiar to the surface 

 of the human body, or to the blood of cadavers, &c., and others 

 especially characteristic of putrefaction, or stagnant water, and so on. 



Clearly the present species is a Bacillus found in water, not neces- 

 sarily stagnant, however, and saprophytic. It is, moreover, aerobic, 

 achroic, and liquefies gelatine at ordinary temperatures, as we have 

 seen. 



If we now inquire what species this form belongs to, there are 

 several decided and well-marked characters to guide us. There are 

 not many schizomycetes known which are so persistently filamentous, 

 and form such large, mycelium-like colonies on gelatine, and whose 

 cells measure over 1'5 fi in thickness ; which, moreover, easily form 

 large, oval spores, and, finally, have such a characteristic stab- 

 culture as this one. 



