YEAST. 



SACCHAROMYCES CEREVISIJE. 



Put upon a slide a drop of liquid that contains 

 actively growing yeast (e.g. brewer's yeast or 

 compressed yeast in Pasteur's fluid], cover and 

 examine, with a low power. Note : 



I. General Characters. 



1. Aggregations of cells into groups. 



2. In the larger individuals protuberances par- 



tially constricted off, buds. 

 Study ivitli a high power, and observe : 



3. Form. 



4. Mode of union. 



5. Size. (Measure.) 



II. Structure. 



1. Cell-wall. 



2. Cell-contents. 



(a) Protoplasm (cytoplasm) : granular, with 



shining spherules. 



(b) Nucleus (not visible in the living state. 



See demonstration of prepared speci- 

 men*). 



(c) Yacuoles : note the number and size. 

 Sketch (X 10). 



* For methods of staining, etc., see "General Biology," by 

 Sedgwick and Wilson, second edition, 1895, p. 219. 



36 



