New York Agricultural Experiment Station. 57 



beginning, at about the middle and at the close of the pouring 

 process. Plates were made using medium 3.20 and the counting was 

 done after 5 days at room temperature. The earliest plates were 

 made with dilutions of 1 to 100, 1 to 500 and 1 to 1000 but the dilu- 

 tions were soon changed to 1 to 10, 1 to 100 and 1 to 500. Six plates 

 were made from each sample and the average of the results from all 

 of the plates was taken as the germ content. 



The germ contents of 32 sets of these comparative samples repre- 

 senting 32 different pails of milk and the relative rank of each sample 

 in its own set, using + for highest, — for lowest and for medium, 

 are given in Table I. 



It is seen from the above table that the average germ content is 

 highest in the samples collected at the beginning of pouring the milk 

 from the pail. The samples taken midway in the emptying process 

 gave the lowest average numbers while those collected at the close of 

 the emptying process had an average germ content midway between 

 the other two sets of samples. These average numbers bear the same 

 relation to each other as 100, 73 and 82. An inspection of the results 

 from the individual sets of samples shows that these average values 

 have little significance since there is very wide variation in the relation 

 of the numbers found in the different sets of samples. 



Since there were three samples taken from each pail of milk the 

 germ content of each individual sample must rank as highest, lowest 

 or medium in its set. This ranking of each sample is indicated in 

 the above table under the heading of rank using + for highest, — for 

 lowest and for medium. These rankings of the samples in Table I 

 are collected for better comparison in Table II. 



Table II. — Summary of Rankings of Samples given in Table I. 



The summary as given in Table II tells quite a different story 

 from the numerical averages in Table I. From this summary it is 



