12 



THE ROYAL SOCIETY OF CANADA 



Experiment II. 



This plot was kept bare of snow from the very first until in the 

 beginning of February high winds and drifting snow made any further 

 snow removal impossible. 



In the five and ten inch levels a slight increase in bacteria was 

 noticed during December, due to the fermentation of dead plant 

 roots. This increase, however, was stopped by the severe frost, and 

 on the fifteen inch level this increase did not take place, there being 

 no plant roots present. 



Later in the winter a very slight increase was again observed, 

 possibly due to a moderation in the frost as since the beginning of 

 February the plot was covered with three feet of snow. 



Conclusions. 



s 



1. Severe frost checked bacterial growth. 



2. A slightly frozen condition of the soil allowed bacterial 

 development. 



3. In December a bacterial increase was noticed where ferment- 

 able material was present. 



Experiment III. 



Table Ilia. 

 Plot Fallowed for Four Years. 

 Average number of bacteria (in millions) per gram of soil at diflferent depths. 



