Ill 



Summary. 

 Average All Sixteen Organisms. 





L and B 

 agar. 



Na. asp. 

 agar. 



NHiNOj 

 agar. 



Starch 

 agar. 



NEUNOs and 

 Starch Agar. 



5 days 



7 days 



15 days 



2.94 

 2.50 

 2 . 56 



1.87 

 1.81 

 2.50 



3.69 

 3.76 

 4.31 



3.10 

 3.00 

 3.06 



2.97 

 3.25 

 2 . 56 



Summary . 

 Average Organisms 6 to 16 Inc. 





L and B 

 agar. 



Na. asp. 

 agar. 



NH,NOj 

 agar. 



Starch 

 agar. 



NH4NO3 and 

 Starch Agar. 



7 days 



15 days 



2.10 

 1.64 

 1.91 



2.10 

 2.00 

 3.00 



3.91 

 3.82 

 4.55 



3.00 

 3.18 

 3.09 



3.10 

 3. 18 

 2.45 



Notes. 



(1) The comparisons between the growth of an organism on the different 

 media were practically as marked at 5 days as they were at 15. 



(2) The five molds Nos. 1, 2, 3, 4, 5, were more easily transferred to 

 sodium asparaginate agar than to some of the media. 



(3) Where molds are included the greatest number of failures of growth 

 occurred on Lipman and Brown agar. 



(4) Studying Nos. 6 to 16 inclusive, it was found that the Lipman and 

 Brown and the Sodium asparaginate agar were about alike in amount of 

 growths produced on slants, and that the ammonium nitrate agar was the 

 poorest media considered. 



(5) When chromogenesis is considered, Starch alone and in combination 

 with the Ammonium nitrate brought out as much chromogenesis as the 

 Lipman and Brown agar. 



Summary of Investigation. 



This paper gives the results of tests made on agar slants where the two 

 media most commonly used for plating soils are compared. The results 



