FUNGI. 



299 



believed that this substance consists of " low " or 

 sedimentary yeast, mixed with Saccliaromyces myco- 

 denna, which forms "ropy beer" (Fig. 59), together 

 with various species of Bacillus, and, in addition, the 



Fig. to. — Mucor-ferment(W, B. Grove). 



Pig. t,'^.— Saccliaromyces mycoderma (W. C. Grove). 



" mucor-ferment " of Pasteur (Fig. 60), which is con- 

 sidered by him as a submerged vegetating form of 

 Mucor racemosus} The following may be accepted 

 as a fair description of the 

 object in question. In ap- 

 pearance it resembles ordi- 

 nary tapioca as sold in 

 commerce. " It is white, 

 in many pieces and variable 

 in form, and when handled 

 is found to be fairly firm, 

 somewhat slippery, and very light. Still, its normal 

 position seems to be at the bottom of the bottle 

 which contains it, until, in the process of change 

 which goes on within, the pieces ascend to the sur- 

 face, and there remain for a time, and presently return 

 to the bottom, so that, whilst the contents are said 

 to be working, these tapioca-like pieces of fungus 

 are constantly ascending and descending. It is evi- 

 dent that carbonic-acid gas is also being fast formed 

 from the sugar, and this too is constantly ascending 



> W. B. Grove, B.A., "Synopsis of Bacteria and Yeast Fungi," 

 p. 67. (1884.) 



