PRODUCED BY ALCOHOLIC FERMENTS. 231 



question was low-fermentation beer, which had completed its 

 storage period, and had been drawn off into bottles and well 

 corked, these three species of Mycoderma must certainly be 

 regarded as very dangerous at this stage of the fermentation. 



The form of Mycoderma cerevisice investigated by me 

 and which, at least some years ago, formed the main part of 

 the Mycoderma growths in the beers of Old and New Carlsberg, 

 and is certainly also at the present time the most essential 

 constituent differs from Lasche's species or races, not only 

 in that it produces no disease in beer as already stated, but 

 also in that it produces no alcoholic fermentation in beer 

 wort. One of Lasche's species yielded 0*26 per cent., two 

 of them produced 0*79 per cent, and the fourth as much as 

 2-51 per cent, of alcohol (by volume) in wort. The growths 

 examined by Lasche and myself are, therefore, distinctly 

 different from each other. 



The main result arrived at is that, amongst the film- 

 forming species ordinarily described under the old systematic 

 name Mycoderma cerevisice^ there is, at least, one species 

 which must be regarded as harmless in the manufacture of 

 beer. This species is very abundant in the Copenhagen 

 breweries, and it formed the subject of my investigations. 



The Mycoderma diseases, which have been recently re- 

 ported from the Stations in Prague and Chicago, are caused 

 by quite different species ; at all events, this applies to the 

 species investigated by Lasche. 



