BACTERIOLOGICAL EXAMINATIONS 231 



ture, and should contain at most only a few small i pin ' 

 holes. It may have some large, irregular ' mechan- 

 ical ' holes where the curd particles have failed to ce- 

 ment. If gas-producing bacteria are very prevalent in 

 the milk, the conditions under which the test is made 

 cause such a rapid growth of the same that the evidence 

 of the abnormal fermentation may be readily seen in the 

 spongy texture of the curd. If the undesirable organ- 

 isms are not very abundant and the conditions are not 

 especially suited to their growth, the ' pin ' holes will 

 be less frequent. 



1 ' Sometimes the curds show no evidence of gas, but 

 their abnormal condition may be recognized by the 

 ' mushy ' texture and the presence of t off ' flavors, 

 that are rendered more apparent by keeping them in 

 closed bottles. This condition is abnormal and is apt to 

 produce quite as serious results as if gas was formed." 



Curd fermentation tests have been suggested for use 

 in connection with the supervision of market milk, and 

 C. E. Marshall has made some observations that tend 

 to show their usefulness for this purpose. L. P.] 



To make regulations in relation to the behavior of 

 milk to these tests would be premature. The general 

 requirement that market milk, and especially infants' 

 milk, shall not be rich in bacteria of putrefaction is suf- 

 ficient for the present. 



d. Bacteriological examinations are made when more 

 information is desired regarding the number and kind of 

 bacteria in milk. As has been said, this differs greatly, 

 even in freshly drawn milk, and it is scarcely possible 

 to state a passing average for the bacterial content of 

 market milk. Nor does it seem to be possible to estab- 

 lish a maximum by ordinance, the violation of which 

 would lead to the condemnation of the milk. Yet, it is 

 of importance to health officers to have an examination 

 made of the number of bacteria in milk sold, since, by 



