INTRODUCTORY 



For this work a knowledge of elementary bacteri- 

 ology and quantitative and qualitative chemistry is 

 indispensable. 

 References — 



Lafar, Handbuch der technischen Mykologie, Jena, 1905 to 



1908. 

 Bulletin p4, Iowa Experiment Station (Soil Samplers). 



Apparatus needed in addition to the list given on 



P-S: 



Two hundred culture tubes. 



Twelve Erlenmeyer flasks, 150 c.c. each. 



Six Erlenmeyer flasks, 500 c.c. each. 



Twelve fermentation tubes. 



One mortar and pestle (wedgewood or porcelain). 



One soil sampler. 



The media required may be made up as the work 

 requiring them comes up. Besides the special media 

 which will be needed a set of media similar to those 

 given for medical bacteriology will be used. See p. 105. 



SECTION I 



QUANTITATIVE DETERMINATION OF BACTERIA AND 

 SPORES IN SOIL 



EXERCISE I. SECURING SAMPLES OF SOIL 



Soil samplers are used and cylinders of soil removed 

 from the upper eight inches of soil. Cylinders of soil 

 should be taken in various parts of the field so as 

 i6s 



