EXAMINATION OF SOIL INFUSIONS. 



EXBKCISE I. 



EXAMINATION OF SOIL INFUSIONS. 



1. Prepare infusions of a sandy soil, a rich loam soil, and 

 a sample of fresh manure by shaking 10 grams in 30 cc. of 

 sterile water for 5 minutes. 



2. Make hanging-drop and stained preparations from each 

 of these infusions and examine under the microscope. 



3. Describe the different organisms present and determine 

 approximately the relative numbers of each. 



4. Compare the number and character of the organisms 

 in the different types of soil and in the manure. 



