2.50 CLEAN MILK 



could detect any lesion or disease. The Committee on Standard 

 Methods, already quoted, gives only guarded recommendations on 

 this point, awaiting further evidence. Those who wish to follow 

 the literature will find an excellent bibliography in the Reports of 

 the Committee (the second report will now soon appear). 



EXAMINATIONS FOR STREPTOCOCCI IN MILK. 



The smear method of Slack (see Report of Committee on 

 Standard Method; also used for the detection of pus in milk) 

 or the recognition and isolation of colonies of streptococci from 

 plates made for counting purposes may be followed. The signifi- 

 cance of streptococci in milk is almost as much in dispute as is the 

 significance of " pus." In general it may be stated that any num- 

 ber exceeding the ordinary number found in milk calls for investi- 

 gation of the dairy supplying the milk, with individual inspection 

 of the cows for mammitis, etc., and critical inspection of methods 

 relating to exclusion of dirt, particularly of manure, from the milk. 

 The standards adopted for the maximum number of streptococci 

 which may be found without calling for such investigations, like the 

 standards for " pus," have varied much in different places. 



STANDARDS FOR PUS AND STREPTOCOCCI.* 



Standards adopted tentatively in Boston have been followed 

 elsewhere and, while no final value can be claimed for them, are 

 quoted below, from a private communication made by Dr. F. H. 

 Slack, Director of the Boston Board of Health Bacteriological 

 Laboratory. The truth seems to be that while injustice may some- 

 times be done to the farmer in condemning a milk for " pus " when 

 as a matter of fact the milk may come from a normal cow con- 

 tributing a number of leucocytes to the milk in excess of those 

 usually contributed by most cows, yet the failure to insist on such a 



* For proposed standards, see pp. 295, 349. 



