136 BACILLUS SUBTILIS AND ITS CONGENERS 



much bran are especially liable to this disease, since it is on this part of the grain, 

 and not on the enclosed flour, that the bacteria reside ; and, as a matter of fact, 

 it is commissariat (military) bread and Graham bread that are most frequently 

 affected, as was pointed out both by Loeffler and UFFELMANN (I.). The latter 

 observer found the Bacillus mesentericus vulgatus to be associated in this disease 

 with a second allied species, viz., the Bacillus liodermos, discovered in cows' milk 

 by LOEFFLER (III.), which owes its other name of "gum bacillus" to the thick 

 gummy appearance of its zoogloea-like cultures on cut potatoes. That the bread 

 disease in question does not make its appearance so frequently as might be 

 expected from the (often very large) number of potato bacilli found in the flour 

 is due to the strongly acid reaction of the dough, which facilitates the extinction 

 of the germs. 



111. Bacillus Fitzianus. 



If a cold-prepared infusion of hay be left to stand at room temperature, there 

 quickly forms on the surface of the liquid a skin composed of various organisms, 

 including the bacillus named above, the chemical activity of which was first 

 examined by A. FITZ (III.). If a little of this skin be transferred to a 

 sterilised solution of 2 per cent, of meat extract and 5 per cent, of glycerin that 

 has received an addition of some 10 percent, of calcium carbonate, then the said 

 microbe develops and acts on the glycerin (C 3 H g 3 ) in such a manner that ethyl 

 alcohol and volatile acids are the chief products formed. Fitz obtained, in two 

 experiments, a yield of alcohol amounting to 25.7 and 25.8 per cent, respectively. 



The fermentation is very brisk, 



o O O * 



and attains its maximum with- 

 in twenty-four hours. 



At the time Fitz made his 

 experiments, no method of 

 preparing pure cultures had 

 as yet been devised. It is 

 therefore of interest to record 

 that his reports were tested 

 by H. BUCHNER (VI.) by the 

 aid of the dilution method. 

 The results were confirmatory, 

 not only of the fermentative 

 activity, but also of the pleo- 

 morphism of this glycerin- 

 ethyl bacterium, which was 

 later named by Zopf Bacillus 

 Fitzianus. As shown in Fig. 

 44, this fission fungus occurs 

 both as cocci and as short and 

 long rods, and is able to pro- 

 duce endospores. Though of 

 no practical importance, it 

 is mentioned here chiefly in 

 order to show that the pro- 

 duction of ethyl alcohol during 

 fermentation can be effected, 

 not only by the higher fungi (yeast in particular), but also by Schizomycetes. 

 This fact is overlooked by many chemists when they speak of " alcoholic fermen- 

 tation fungi," meaning thereby yeast alone. 



Allied to the last-named bacillus as regards fermentative activity is the 



OO CO 



FIG. 44. Bacillus Fitziunus. 



a, b, f, g. Cocci gradually changing into short rods, then (c, e) 

 into long rods ; d. The same with an cndospore. Magn. 

 4030. (After H. Buchner.) 



