THE EXAMINATION OF MILK 325 



COWS eating certain plants, but there are a number of 

 bacteria which give rise to bitterness in milk ; the chief 

 of these are the butyric acid ferments. Other organisms 

 giving rise to bitterness in milk have been described by 

 Weigmann, Conn, Duclaux and Preudenreich. 



Stringy Milk. — Owing to the action of micro-organisms, 

 milk frequently becomes filamentous or stringy in character. 

 This milk disease is much deprecated in Switzerland, where 

 milk so diseased cannot be employed in the manufacture of 

 certain cheeses. The milk, after twelve or fourteen hours, 

 assumes a sticky character, which sometimes is so marked 

 that the liquid can be pulled out into strings if the finger 

 be dipped into it. The Norwegian national drink, known 

 as tcettemcelk, is a preparation produced with the aid of 

 the ' stringy ' milk bacillus. Amongst the many organisms 

 producing stringiness in milk, the following are perhaps the 

 most important : 



Bacillus lactis pituitosi. — This organism was isolated by 

 Lof&er, who describes it as a stout, slightly curved rodlet, 

 which does not liquefy gelatine. 



Bacillus lactis viscosus.— This organism, which renders 

 milk very stringy and is known as the viscid-milk bacillus, 

 was first isolated by Adametz. It is a very short rodlet, 

 aerobic, and does not liquefy gelatine. At the ordinary 

 room temperature the milk does not become markedly 

 stringy for some time. 



Streptococcus Hollandicus. — This organism of stringy milk 

 is used in Holland in the manufacture of Edam cheese. 

 The organism is a coccus which occurs in the form of 

 chains. It does not liquefy gelatine ; it renders milk stringy 

 within twelve to fifteen hours at a temperature of 77° C, 

 the milk becoming sour at the same time. 



Soapy Milk. — Milk which first appears to be normal often 

 acquires a disagreeable soapy taste in from twelve to twenty- 



