New Yokk Agricultural Experiment Station. Ill 



Stocking. Nearly one-half of them differed so materially from 

 the types described by the above authors that they were listed 

 under their nearest allies with the addition of an interrogation 

 point for the double purpose of indicating their general relation- 

 ship and of avoiding the coinage of any more names. The re- 

 maining 40 per ct. come more or less clearly under the shadowy 

 outlines of the types of Conn and his colleagues. 



Under the heading " cultures studied " is given the number of 

 cultures which were studied in detail and whose group number 

 was fully determined. A larger number of cultures were given 

 a preliminary study, sufficient to convince the worker that the 

 culture finally studied in detail was a true type of the class of 

 colonies which it was taken to represent. The extended study 

 of a considerable number of cultures of the same group indi- 

 cates not so much the frequency with which the cultures were 

 encountered as the variation in colony appearance which ren- 

 dered the identity doubtful in the mind of the observer. 



The present group number is not perfect and in some cases two 

 or more really distinct strains are undoubtedly included in a 

 single group. The probability of such inclusion is greater in the 

 groups having dissimilar colonies as noted above. It should be 

 noted that whatever criticism is directed against the Society 

 classification system because it does not separate all distinct 

 strains bears even harder on the older classification since none 

 of these collections of cultures which were grouped together by 

 the Society system were separated by the older grouping. 



The udder organisms undoubtedly enter through the teat open- 

 ing and advance into the finer subdivisions of the udder at times 

 against the force of gravity and the flow cf milk. Under such 

 circumstances it would seem that swimming organs would be a 

 contributing factor in their struggle for existence. Since the 

 genus bacillus — motile rods — is absent from the above list of 

 udder organisms it is probable that flagella are correlated with 

 something else which is distinctly unsuited to udder conditions. 



The genus Streptococcus is also conspicuous because only two 



