STUDY OF TEA8T. 99 



3. What substances are produced by the 



growth of yeast? 

 D. Microscopic study of yeast. (In class.) 



By means of a pipette put a drop from the 

 bottom of a yeast mixture on a glass slide; 

 cover with a thin cover-glass, and examine 

 under the high power of the microscope. 



1. What is the color of the solid bodies (yeast- 



cells) which you see ? 



2. Yeast-cells form new cells by budding, the 



bud (daughter-cell) usually remaining 

 attached to the cell (mother-cell) which 

 produced it. 



a. Draw a group of cells showing a 

 mother-cell and two daughter-cells. 



3. Can you distinguish a nucleus in any of the 



yeast-cells? (The colorless vacuole is 

 not the nucleus.) 



4. Place a drop of stain (eosin or methyl vio- 



let) on the slide at the edge of the cover- 

 glass, allowing it to run beneath the glass 

 to stain the cells. Can you make out 

 any further facts regarding the structure 

 of yeast? 



5. Add a drop of iodine to a little yeast mix- 



ture and examine with the compound 

 microscope. What kind of bodies are 

 mixed in with the yeast-cells? What 

 does their color indicate as to their com- 

 position? 



