Mar. 24, 1919 



Ammonification of Manure in Soil 



327 



soil from Plot I made at intervals for a period of three years. It will 

 be noted that during that time the non-spore-forming Ps. cauidatus 

 appeared only once and then in comparatively small numbers; Ps. 

 fluorescens appeared nine times, and only twice constituted more than 

 I per cent and never more than 2.5 per cent of the total flora. It is 

 also a significant fact that the spore-forming B. cereus was always present 

 and made up from 0.55 to 4.4 per cent of the total flora. Another 

 plating made just previous to the present work showed that the organ- 

 isms were present as follows: Ps. fiiwrescens , 2 per cent; Ps. caudatus, 

 less than o.i per cent; and B. cereus, 2.4 per cent. 



Table X. — Comparison between numbers of Bacillus cereus and numbers of certain 

 non-spore formers in soil from Plot I. Soil manured and kept in the laboratory. 

 Series II 



HORSE MANURE 

 [Counts indicate the number of colonies per grajn of soil] 



COW MANURE 



3- 

 4- 

 S- 

 7- 

 8. 

 9- 

 II. 

 13- 

 IS- 

 17- 



164, 000, 000 

 93,000,000 

 98, 500,000 



127,000,000 

 55,000.000 



490, 000, 000 



251,000,000 

 52,000,000 



412,000,000 

 67,000,000 



395,000. 000 



2 J5. 000, 000 



Trace 



Trace 



500,000 



3,500,000 



500,000 



1,000,000 



1, 500,000 



1,000,000 



2,500,000 



Trace 



5,000.000 



None 



Average. 



Trace. 



Trace. 



None. 



None. 



None. 



None. 



None. 



500,000 



7, 500, 000 



None 

 10,000,000 

 1,000,000! 



27, 5000,00 



64, 000, 000 



67,000,000 



81,000.000 



101,000,000 



42,000,000 



65, 500,000 



34, 500,000 



330,000,000 



323,000,000 



330,000,000 



350,000.000 



Trace 



2,000,000 



1,800,000 



None, 



None 



1 , 500, 000 



Trace 



None, 



Trace 



Trace 



Trace 



2,000,000 



a B. cereus did not develop on the plates. 



Tables IX, X, and XI record the results of platings made from samples 

 of the same soil after being treated with fresh manure. Examination 



