84 GENERAL MICROBIOLOGY 



10. Record the time of fermentation and the relative 

 fermentation of each yeast and draw conclusions from 

 your results. 



11. Do your results coincide with those in the refer- 

 ences given? 



12. State in detail your results with any conclusions 

 which follow from them, and point out the practical applica- 

 tions which may be made. 



By the use of sugar broth in place of wort, this method 

 may be employed for bacteria as well. 



REFERENCES 



LAFAR: Technical Mycology, Vol. II, Part 1, pp. 113, 114, and Part 2, 

 pp. 401-407, 430-436. (Index of three volumes is in Vol. II, 

 Part 2.) 



GREEN: Soluble Ferments and Fermentation, pp. 333-362. 



CONN: Bacteria, Yeasts and Molds, pp. 56-99. 



EXERCISE 26. LINDNER'S DROPLET CULTURE 



The object of the exercise is to isolate a single yeast 

 cell and watch its development. 



Apparatus. Sterile cover-glass (sterilize in flame); con- 



FIG. 30. Lindner's Droplet Culture. (Adapted from Lafar's Tech- 

 nische Mykologie.) 



cave slide; forceps; sterile toothpick (sterilize in a test 

 tube in hot air) ; paraffin; India ink. 



Culture. Pure culture of some yeast. 



Method. 1. Inoculate a tube of cider with yeast. 

 Distribute the organisms well. 



2. Using the sterile toothpick, make five rows of small 



