STUDIES ON FERMENTATION. 129 



On June 15tli ra3'celium was very abundant, and was borne up 

 by bubbles of gas. In addition to this there were a few scattered 

 patches of bubbles on the surface of the liquid, showing that 

 fermentation had commenced. 



On June 16th fermentation continued to show itself by the 

 frothy state of the crusts of mycelium buoyed up by the 

 bubbles of gas. 



On June 17th we attached B and C separately, as indicated 

 in Fig. 19 (p. 101) to test-flasks, into which we transferred 

 nearly all their contents. Some clusters of entangled filaments of 

 mycelium remained on the surface of the liquids in the test-flasks. 



On June 18th a very slow fermentation commenced in the 

 test-flasks; it continued for some days without becoming more 

 active. A little bubble would slowly rise from the bottom of 

 the vessel, succeeded after a short interval by another, and so 

 on. The temperature of the oven was 24° C. (75° F.). On 

 June 22nd we raised it to 28° C. (82° F.). The fermentation 

 became more rapid, a constant succession of bubbles rose 

 quickly from the bottom of the test-flasks ; still there was none 

 of the vivacity of an alcoholic fermentation produced by yeast. 



On June 25th the fermentation was in much the same con- 

 dition, if anything rather less active. 



On June 28th temperature 25° C. (77° F.) ; fermentation 

 had stopped. 



On June 29th we raised the temperature to 27° C. (81° F.) 

 again, and some slight revival of fermentation manifested itself. 



The increase in temperature, therefore, as might have been 

 expected, exercises a considerable influence on this kind of 

 fermentation. 



The vessels were then left to themselves, and during the 

 course of three months they did not show the least sign of 

 fermentation ; moreover, we did not observe, either on the 

 interior walls of the empty flasks, or on the surface or through- 

 out the body of the liquid in the test-glasses, any fungoid pro- 

 duction or organism whatever different from mucor itself. 



The same observations apply to the vessel A ; in this case the 



K 



