[9] 



^be IRutritive Iprocceeee in Saccbaromijcee. 



By Henry C. A. Vine. 

 Plate I. 



I^HE writer has been asked to embody, in a definite form, 

 some observations on this subject, made before the Bath 

 Microscopical Society : he has felt great hesitation in so 

 doing, as the subject involves many points of controversy, into 

 the discussion of which his want of leisure forbids him entering. 



The actual nature of the processes of nutrition in the Muco- 

 rim\ the Schizophytes, and the Saccharomycetes^ have not, so far as 

 the writer is aware, been the subject of any special research. 

 The nature of the materials on, or in. which they flourish, and the 

 results of their vitality, are well known, and the knowledge is 

 made subservient to the wants of everyday life, as in the manufac- 

 ture of wine, beer, and bread. In fact, the decomposition of 

 saccharine matter (carbo-hydrates) and the evolution of alcohol 

 and carbonic-acid gas by the action of minute fungi is among the 

 earliest lessons of the physiological student. But meanwhile we 

 remain ignorant of the exact manner in which these organs 

 assimilate their food, and of the precise condition in which it is 

 necessary for it to be presented to them. 



For such studies the Saccharomycetes appear to present the 

 greatest facilities, being readily obtained in a fairly uniform condi- 

 tion, and being from their size readily separated to a sufficient 

 degree from more minute organisms. The S. vini^ S. cerevisicE, or 

 the 5. Pastoriamis would equally serve our purpose, but the S. 

 cerevism is in all ways the most convenient, especially as the 

 amount of knowledge concerning this species already in hand 

 greatly facilitates investigation. It comprises several distinct 

 varieties, which, as long as the cultures remain pure, retain well- 

 defined characters. The shape of the cell, the structure of the 

 cell-wall, and the nature of the cell-contents, all present definite 

 points of difference, and call for a greater amount of classification 

 than they have yet received. 



The study of their nutrition may be conveniently made under 

 Journal of Microscopy and Natural Science. 



New Series. Vol. II. 1888. g 



