ANAEROBIOSIS. 181 



of locomotion. Nevertheless he laid but little stress on this dis- 

 tinction, the point being one of minor importance in comparison 

 with the property he recognised in this "vibrion butyrique" viz., 

 the faculty of existing without 'air. This observation formed 

 one of the main supports on which this gifted philosopher founded 

 his theory of fermentation, mentioned in 16, and with regard to 

 which a few additional remarks will now be made. 



At present we have first to consider the said peculiarity by 

 itself, irrespective of the resulting decomposition effected in the 

 nutrient medium. Creatures requiring oxygen for the continu- 

 ance of their existence are termed aerobiontes, whilst the term 

 anaerobiontes, or, shortly, anaerobes, is applied to creatures capable 

 of development in the absence of this gas. A distinction is drawn 

 between two sub-groups, viz., strictly anaerobic organisms, i.e. 

 such as can live only in an environment devoid of oxygen, and for 

 which this gas is therefore a poison ; and facultatively anaerobic 

 organisms, i.e. those to which oxygen is neither injurious nor 

 essential, and which can consequently thrive either in presence 

 or absence of air. Thus, for example, the acetic acid bacteria are 

 strictly aerobic, certain lactic acid bacteria facultatively anaerobic, 

 and the majority of the butyric acid bacteria strictly anaerobic. 



At the present time numerous species of anaerobic fission fungi 

 are known. PASTEUR (IX.) himself, in 1863, associated with the 

 "vibrion butyrique" a second anaerobic species, viz., the microbe 

 which sets up fermentation in calcium tartrate. This process of 

 decomposition, already observed by Noellner, but which requires 

 more careful investigation, often occurs spontaneously in tartaric 

 acid works, destroying the tartaric acid and occasioning great loss. 

 The different species of butyric acid bacteria will be thoroughly 

 discussed later on. At present, by reason of their general interest, 

 the known pathogenic anaerobic species, three in number, will be 

 considered. The first of these, as regards priority of discovery, is 

 the "vibrion septique," found by PASTEUR, JOUBERT, and CHAMBER- 

 LAND (I.), and subsequently examined more closely by R. Koch 

 and Gaffky, and now generally known to bacteriologists as Bacillus 

 cedematis maligni. According to an opinion expressed by Pasteur, 

 this bacillus is identical with the one effecting the fermentation of 

 calcium tartrate. The decompositions set up by the bacillus of 

 malignant oedema in nutrient media containing carbohydrates were 

 studied by R. KERRY and S. FRAENKEL (I.). Grape-sugar yielded 

 ethyl alcohol, ethylidene lactic acid, and butyric acid. From 

 calcium lactate were produced butyric acid, a little formic acid, 

 and propyl alcohol. Milk-sugar and also cane-sugar were gradu- 

 ally fermented to ethyl alcohol, formic acid, butyric acid, and 

 ethylidene lactic acid. Starch was also attacked, and yielded the 

 three last-named acids. With Bacillus cedematis maligni have 

 been associated two other pathogenic anaerobic species of fission 

 fungi, namely, the bacillus of symptomatic anthrax, by Feser 



