224 Report of the Department of Bacteriology of the 



four tests of Table XI) the difference has been very pronounced. 

 Brown's agar has given slightly higher counts than the asparaginate 

 agar in three of the nine tests of Table XII, but in the other six tests 

 has given much lower counts than the asparaginate agar; and in 

 Table XIII has given higher counts than on the asparaginate agar 

 in five of the twelve tests. Temple's agar has given higher counts 

 than the asparaginate agar in six of the twelve tests listed in Table 

 XIII. These counts show that the asparaginate agar is adapted to 

 the growth of at least as large a number of soil bacteria as any of the 

 other agar media; in this respect it is superior to them rather than 

 inferior, and is unquestionably superior to Lipman and Brown's 



Table XII. — Tests of Brown's Culture Medium. 



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

 than the corresponding counts upon Brown's agar are printed in bold-faced type. 



t In these cases there was such irregularity between the counts from the parallel 

 plates that a satisfactory average could not be taken. 



X The medium used in making these counts contained 0.2 per ct. asparaginate and 

 only 0.05 per ct. dextrose. 



agar. It has been found to allow much greater distinction in appear- 

 ance between different kinds of colonies than Fischer's agar, slightly 

 greater than Temple's, while it is certainly not inferior in this matter 

 to Lipman and Brown's or to Brown's formula. In respect to definite 

 chemical composition, as already stated, it is superior to all four. 



Table XIII is of particular interest because all six of these media 

 were included in this series of comparative tests. In these twelve 

 tests there was very little variation between the counts obtained 

 upon the different media. They do not even show the usual superi- 



