317 



of view, that there appeared some chance of further unraveüing it. Though hitherto 

 I have by no means entirely succeeded, I think, nevertheless, that what follows 

 holds good. 



Three species of obligatous ariaërobics are in particular concerned with the 

 putrefaction of proteids. In the first place Bacillus septicus, secondly a group of ex- 

 tremely variable forms, related tn the tetanusbacillus, and to which I will give the 

 name of »skatol-bacteria«, and thirdly, an immobile, well-characferised species, called 

 by me B. pseudopulcher. For separating these different species, I used a ciüture ge- 

 latine of the following composition: Destilled water, lopCt. gelatine, 3 pCt. pepton 

 siccum, 0,05 pCt. dinatrium phosphate, 0,05 pCt. magnesium sulphate, using at the 

 same time yeast or a blastomycete for withdrawing the oxygen. When put into a deep 

 experiment-tube, the anaërobics develop even with free entrance of air. 



B. septicus Pasteur, is, according to my experience, one of the most spread 

 species of bacteria, to be found wherever animal substances are tainting, and very 

 common in dust and in the soil. It is an easily recognisable and well defined species. 

 A virulent form of it goes in the German literature by the name of B. oedematis 

 waligiu '^). Material of the latter, occuring in the laboratoria. I compared, also with 

 a view to their relation to oxygen, with cultures of B. septicus. repeatedly isolated by 

 mefrom putrefying albumen solutions, or fibrine, infected with garden-soil, but I could 

 discover no difference. 



The skatol-bacteria are to be known by the globular spores which are found in 

 proteine putrefactions, in the swollen ends of thin, commonly long staves. One of the 

 forms isolated retained at first, even in the pure cultures, globular spores, whilst in 

 other isolations the spore-form proved not to be constant. The dimensions of spores 

 and staves are most variable. Motion, if present, is slow, in pure cultures sometimes 

 absent. Glucose, added to the above mixture, gives rise to the production of gas. The 

 colonies cause the culture gelatine more to weaken than to liquefy; they are sometimes 

 colorless, commonly, however, surrounded with a brownish aureole. The study of this 

 species is difïicult on account of the great variability in form and functions, which 

 renders the experiments doubtful and often suggests infection with allied forms to 

 which their common occurrence gives particular cause. 



W'hile skatolbacteria never fail in putrefying substances, B. septicus may be ab- 

 sent and its place be taken by B. pseudopulcher. This name was chosen on account 

 of its resemblance to a common earthbactery, related to B. megatheriuui, and which 

 I baptised B. pulcher-). Motion is never observed in pseudopulcher : the spores are 

 oblong, larger than in B. septicus, frequently to be found in long rows within the 

 threads, generally, however, they occur in short staves. The colonies, which liquefy 

 strongly, have a smooth surface, by which they may be easily distinguished from 

 B. septicus. They are characterised by a heavy sediment, consisting of staves and 

 spores. This sediment is dift'erent, or wanting in B. septicus. The pure cultures deve- 

 lop gases but not many stinking products. There is often a distinct smell of cheese 



') A bactery, accepted by the mcdical men as a particular species. B. Cliaiiveaui 

 (of the French) or B. e>npliysematos (of tlie Gcrmans) is, in my opinion, only a va- 

 riety of it. 



-) At present in trade by the name of »alinit«. 



