2032 Journal of Applied Microscopy 



to confine our attention to those species that were more or less constantly 

 present in the milk of all the cows, and to make a complete study of those 

 existing in the udder of one particular cow. 



The numbers of bacteria present in both the fore and after milk of the vari- 

 ous cows, and of the same cow, and even in the different quarters of the udder 

 of the same cow were so widely different that little stress can be laid upon an 

 exact enumeration. 



The following examples, which are typical of numerous others, will illustrate 



the point : 



Determination 1. 

 86,400 per c. c. 

 - 120,000 

 40,800 

 57,600 



Determination 2. 



Fore milk, right front teat, - - - 48,000 per c. c. 



" hind " - - - 24,080 



" left front " - - - 22,400 



" hind " - . - 35,100 " 



Cow No. 2. Determination 1. 



Fore milk, - 200-500 per c. c. 



After milk, ------ 0-100 



The results of a large number of determinations, of which the above are 

 typical, showed on an average 25-50,000 germs per c. c. in the fore milk. The 

 numbers in the strippings, or after milk, varied greatly with the manner of taking. 

 For example, when the milking was done quickly, but very few and sometimes 

 no colonies were found in the " strippings ;" whereas, when the milking was 

 done slowly and some time lost before the samples from the last milk were 

 taken, the number of bacteria was very variable, being in one case as high as 

 57,000. 



The important point, therefore, is not the exact number, but the fact that 

 bacteria were found in large numbers, not only in the fore, but in the middle 

 and last milk of nearly all the cows tested. 



The number of species present in the udders of cows is comparatively small. 

 Of this number, some are more or less constantly present, whereas others are 

 very variable in their presence. Of those species which are present, the char- 

 acters are in many cases so slightly marked that their identification proved a 

 very difficult matter. In fact, with the exception of Bacillus acidi lactici, not a 

 single species discovered was strongly characterized. A number had a very 

 slow or no effect upon milk, and even the digestors were in every case very slow 

 digestors. But this matter will be more fully discussed after a description of 

 the species has been given. 



B. acidi lactici (Conn, No. 206), B. acidi lactici (Conn, 202), and B. lactis 

 cerobafis (Conn, 197), Nos. I, II, and III, are the only ones that have been found 

 constantly present in all the samples, and in every case they have composed at 

 least 95 per cent, of the germs present. The species to be subsequently described 

 have been only more or less variably present, and in no case have been found 

 in large numbers. 



