Few York Agricultural Experiment Station. 223 



only two of the twenty-two tests listed in Tables XI and XIII. 

 Brown's agar gave as high a count as the gelatin only once in the 

 nine tests given in Table XII, and four times in the twelve tests 

 of Table XIII. Temple's agar gave a higher count than the gelatin 

 in just three of the twelve tests listed in Table XIII. These counts 

 show that these four agar media, like the asparaginate agar, permit 

 the growth of fewer soil bacteria than does the gelatin. None of 

 them allow as good distinction in appearance between the different 



Table XL — Tests of Lipman and Brown's Culture Medium. 



* Counts upon asparaginate agar and upon soil-extract gelatin that are higher than 

 the corresponding counts upon Lipman and Brown's agar are printed in bold-faced 

 type. 



t The medium used in making these counts contained only 0.05 per ct. asparaginate. 



X This count is inexact because of rapid liquefaction. 



colonies as does gelatin. With the exception of Lipman and Brown's 

 agar, none of them have any advantage over the gelatin in the 

 matter of definite chemical composition. 



The same tables show how the counts obtained upon the aspara- 

 ginate agar compare with those obtained upon the other four agar 

 media. Fischer's agar gave a higher count than the asparaginate 

 agar in five out of the seven tests listed in Table X, but in only four 

 of the twelve tests included in Table XIII. Lipman and Brown's 

 agar gave higher counts than the asparaginate agar in only four of 

 the twenty-two tests included in Tables XI and XIII, and then 

 always by a very narrow margin; while in several of the tests in which 

 it has given a lower count than the asparaginate agar (as in the last 



