188 MICRO-ORGANISMS AND FERMENTATION. 



pure culture. They exhibited marked differences in their 

 sedimentary forms and in ascospore-formation. The species 

 which were introduced into practice also differed in this 

 respect. Delbruck, P. Lindner, and Stenglein have also had 

 the same experience. 



Belohoubek, Schumacher and Wiesner, have carried out 

 microscopical and chemical investigations of yeasts of the kind 

 last mentioned, and Belohoubek's " Studien iiber Presshefe " 

 (Prague, 1876) especially contains accurate descriptions of 

 the appearance under the microscope of ordinary pressed 

 yeast in the different stages of its development, and observa- 

 tions on the microscopic indications of the quality of the 

 manufactured yeast, so far as can be judged from the contents 

 of the cells. The decomposing yeast cells show a change in 

 the colour and consistence of their plasma ; this gradually 

 becomes darker and liquid, the vacuoles become larger, and 

 the sharp outlines between the vacuoles and the plasma 

 gradually disappear, the plasma shrinks from the cell-wall 

 and finally collects in irregular masses in the cell-fluid ; 

 these also disappear at last, and finally the cell- wall is 

 dissolved. According to the above authors, there also occur 

 in pressed-yeast, cells which suddenly develop a number of 

 small vacuoles ; these " abnormal vacuolar " cells quickly 

 perish. 



OTHER BUDDING-FUNGI. 



(Torula, Saccharomyces apiculatus, Mycoderma 



cerevisice and vini.) 



In the following pages we give a review of some other 

 fungi, which are of more or less importance in the fermen- 

 tation industries, and which resemble the Saccharomycetes 

 in that they multiply by budding ; these species develop a 

 mycelium only exceptionally. On the other hand they are 

 all distinguished from the Saccharomycetes by the absence of 

 the property of forming endogenous spores which characterises 

 the latter. 



