FUSARIUM. CHALARA. 217 



material for this fungus, especially when the yeast is in a 

 quiescent state at the end of the fermentation. Sometimes a 

 microscopic examination has shown an enormous number of 

 conidia. It is not known what influence such a growth ex- 

 ercises on the quality of the yeast and the beer, but without 

 doubt it is advisable to avoid the fungus as much as possible. 

 It forms vigorous growths on pressed yeast also, which have 

 a deleterious action on the quality of the yeast. A large 

 number of species and varieties find shelter under the name 

 O. lactis. Weigmann has identified several, and Grimm also 

 isolated a number of forms from sour milk, cheese, etc., which 

 differ clearly from each other both in regard to their character- 

 istic growths on gelatine, and especially on potatoes, and also 

 in regard to their peptonising action on the substratum. 



7. Fusarium. 



The red colour occasionally occurring on malt grains is 

 due to various fungi, among which is a Fusarium described by 

 Matthews and Klein. The mould formation begins on the 

 germinating part of the grains, and thence spreads over its 

 surface. The filaments of the mycelium, which show globular 

 swellings, are connected by numerous bridgings. The red 

 colouring matter is present in the contents of the filaments. 

 On a moist medium the membranes gradually swell, forming 

 a slimy envelope, which is coloured violet by iodine. The 

 oval conidia germinate either directly, or previously grow 

 into sickle-shaped multiple cells. Germinating filaments issue 

 from the points of the latter, and by slow degrees the cells 

 swell up. Both the mycelium and the sickle-shaped conidia 

 are able to produce thick-walled spores like gemmae. The 

 fungus does not appear capable of hindering the growth of 

 sound malt grains, even if its mycelium spreads freely over 

 their surface. Generally speaking, it only attacks diseased 

 grains. 



8. Chalara. 



Chalara mycoderma (Fig. 43) is described in Pasteur's 

 Etudes sur la biere as one of the organisms commonly occurring 



