New York Agricultural Experiment Station. 121 



believed that these 45 groups can be safely considered as true 

 members of the udder flora. 



It is seen that Nos. (3, 9, 17, 24, 29 and 30 were obtained from 

 the udders of four or more of the 15 cows. Expressed in the 

 older nomenclature the first two of these are Bacterium lactis 

 non-acidi, the next two are variant strains associated with Bac- 

 terium lactis varians, No. 29 is Bacterium lactis albidus and the 

 last is also Bacterium lactis varians. Of these cultures Nos. 29, 

 24 and 17 were the most common, having been found in 8, 7 and 6 

 udders, respectively. 



The cultures isolated from the samples obtained on a single oc- 

 casion from another herd cannot all be assigned to the udder flora 

 with the same assurance as those given above, but the certainty of 

 their having been derived from this source is increased in propor- 

 tion to the number of udder samples in which they were observed. 



The culture numbers noted m the 184 samples from the herd 

 of Mr. A. G. Lewis and the number of samples in which each 

 was found are given in Table XII. 



Table XII. — Frequency of Isolation of Udder Forms from 184 Samples. 



The culture numbers given in bold face in the above table are 

 those previously noted in Table XI. Finding them in the udders 

 in this separate herd, many members of which had been recently 

 imported from the Island of Guernsey throws some light Upon 

 their international distribution. Of the forms not previously en- 

 countered a number of them occurred in so many samples there 

 can be no doubt of their being true members of the udder flora. 

 The most doubtful forms are those found in but one or two sam- 

 ples. They would have been excluded from the list had any sus- 

 picious circumstance been observed in connection with their isola- 



