70 



Dairy Bacteriology. 



stringing out into long threads, several feet in length, as 

 in Fig. 17. Two sets of conditions are responsible for these 

 ropy or slimy milks. The most com- 

 mon is where the milk is clotted or 

 stringy when drawn, as in some forms 

 of garget. This is generally due to the 

 presence of viscid pus, and is often ac- 

 companied by a bloody discharge, such 

 a condition representing an inflamed 

 state of the udder. Ropiness of this 

 character is not usually communicable 

 from one lot of milk to another. 



The communicable form of ropy milk 

 only appears after the milk has been 

 drawn from the udder for a day or so, 

 and is caused by the development of 

 various species of bacteria which find 

 their way into the milk after it is drawn. 

 These defects are liable to occur at any 

 season of the year. Their presence in 

 a dairy is a source of much trouble, as 

 the unsightly appearance of the milk 

 precludes its use as food, although there 

 is no evidence that these ropy fermen- Fl - 17 - R P V milk - 

 tations are dangerous to health. 



There are undoubtedly a number of different species of 

 bacteria that are capable of producing these viscid changes, 1 

 but it is quite probable that they are not of equal im- 

 portance in infecting milk under natural conditions. 



In the majority of cases studied in this country,* the 



1 Guillebeau (Milch Zeit., 1892, p. 808) has studied over a dozen different forms 

 that possess this property. 

 * Ward, Bull. 165, Cornell Expt. Stat., Mch., 1899; also Bull. 195, Ibid., Nov., 1901. 



