BY R. GREIG-SMITH. 



669 



grm. At 28°, the rise was steady, and by the eightieth day, the 

 numbers lay between 25 and 'M) miUions. 



A variation of tlie preceding experiment was made by using a 

 poor sandy soil, and incubating the tests at 22°. The soil, which 

 contained Amoeba Umax, was treated with 4% of chloroform for 

 two days, and the moisture was brought up to 17%. As, however, a 

 strong growth of moulds developed upon the surfaces of the soils 

 in the tests, the moisture was, by the thirty-seventh day, allowed to 

 fall to 13%, at which it was maintained. 



Experiment v. — The Addition of Soil and its Extracts. 



