DEGRADATION OF PROTEIDS, ETC. 369 



sluggish fermentation, 4-5 per cent, of alcohol being formed. 

 Galactose by itself was more difficult to ferment, the process 

 ceasing on 2-3 per cent, of alcohol being formed. Maltose (1-2 per 

 cent, of alcohol) and lactose (2-3 per cent, of alcohol) behaved in 

 a similar way ; and their fission anterior to fermentation is difficult 

 to determine. In presence of air, the fungus readily consumes 

 alcohol, even when as already mentioned 10 per cent, is added 

 to the culture liquid. Nearly the whole of the sugar in a 10 per 

 cent, solution disappears, within twelve days, when in contact 

 with the surface vegetation of the fungus at 25 C., without more 

 than 0.2 per cent, of alcohol being detectable. There is nothing 

 remarkable in this, in view of the aforesaid fact (reported by 

 Wehmer) that sowings of conidia of Asp. niger and Penic. glaucum 

 on a 3 per cent, solution of alcohol (as the sole organic food-stuff) 

 and inorganic nutrient salts, will develop to complete vegetative 

 coatings ; whilst, according to Duclaux, these cultures of Asp. 

 niger will also decompose 6-8 per cent, of alcohol. 



294. The Degradation of Proteids and their 

 Derivatives. 



The property of liquefying gelatin is so general among the 

 filamentous fungi, including the Aspergillacece, that only the 

 exceptions are .really of interest. The rapidity of this lique- 

 faction and probably sometimes also the time of its inception 

 depends largely on special conditions (the concentration and 

 reaction of the gelatin, the presence or absence of certain sub- 

 stances, the temperature, &c.). Even the same species does not 

 always behave in the same way, and therefore the appraisement 

 of its diagnostic value is probably on a par with the case of 

 bacteria (see vol. i. p. 299), though the feature possesses a certain 

 importance in any event. The liquefactive power of Penic. 

 glaucum seems to have been first investigated by A. HANSEN (I.) 

 in 1889, and that of Asp. niger by BOURQUELOT (XII.) in 1894. 

 A tentative comparison, with streak cultures in 10 per cent, wort 

 gelatin at 15 C., by WEHMER (XII.) showed that Asp. glaucus and 

 A. fumigatus liquefy a gelatin very slowly, the results* not being 

 appreciable until several weeks have elapsed ; whereas about half 

 the gelatin was liquefied in ten days by A. niger, A. oryzce, 

 A. candidus, A. minimus, A. novus, A. ostianus, Penic. glaucum, 

 P. luteum, P. italicum, and P. olivaceum ; and, according to 

 WEHMER (XVII.), Asp. clavatus, A. flavus, A. Wentii and 

 A. giganteus act with equal promptness. SCHAFFER (IV.) has 

 also published the results of experiments in the same direction, 

 and with about the same fungi. If well-defined conditions be 

 maintained, the results may be utilised for diagnostic purposes ; 

 at any rate, the secretion of the liquefactive enzyme is not 

 retarded by the presence of sugar. Only scanty information is 



