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THE ROYAL SOCIETY OF CANADA 



As Harden did not agree with the other investigators as to the 

 cause of the increase in the number of bacteria in frozen soils, and 

 mentioned the possibiHty that bacteria should be brought mechani- 

 cally to the surface under the influence of the moisture movement from 

 unfrozen to frozen soil, samples were taken at different depth, so 

 that the numbers of bacteria present on the different levels, 4", 8", 12", 

 16" etc. could be ascertained simultaneously. Experiment IV was 

 planned to test this assertion of Harden that the action of the frost 

 by lifting soil water from the lower not frozen soil levels mechanically 

 increases the numbers of bacteria in the frozen soil. 



BIBLIOGRAPHY. 



1. H. J. Conn. Ithaca, N. Y. 



"Bacteria in Frozen Soils." I. and II. 



Centralb. fur. Bakt. Abt. II. Bd. 28, page 422. 



Bd. 32, page 70. 



2. W. M. EsTEN. Storrs., Conn. 



No results published, but Conn's results confirmed in personal letter. 



3. P. E. Brown and R. E. Smith, 



"Bacterial Activities in Frozen Soils." 



Iowa State Coll. of Agr., Res. Bull. 4, Jan., 1912. 



4. E. C. Harden, 



"The Occurrence of Bacteria in Frozen Soils." 

 Botan. Gazette, Vol. LXL, No. 6. Page 507. 



5. H. J. Conn. 



"Bacteria of Frozen Soils." 



N. Y. Expt. Stn., Tech. Bui. 35. July, 1914. 



Experiment I. 



Table la. 

 Average number of bacteria at different depths. Field plowed and manured. 



