GENUS BACTERIUM 3&& 



ment both on the surface and in stabs. The surface growth- 

 consists of a large number of small colonies, often more or less 

 confluent so as to form a delicate veil. The stab is fairly 

 vigorous and granular. Milk, as mentioned above, is the most 

 favorable medium. It is coagulated more slowly than by 

 Strept. lacticus, usually not before 48 or 72 hours at 37 C.> 

 often longer. Coagulation takes place more rapidly at 42 C. 

 than at 37 C. and the power of acid-production is increased 

 somewhat by reinoculation from tube to tube of milk at 42 

 as soon as the curd is formed, i.e., the interval shortens. The 

 coagulum is soft, smooth, and easily broken up. Whey is 

 rarely separated. Some strains form sliminess of the milk, 

 but this power is readily lost. Milk cultures have a peculiar 

 cheesy butyric- acid odor and the taste after about 10 days is 

 extremely acid and acrid. 



"Ordinary laboratory media, such as plain agar, broth, 

 potato or gelatin, allow little or no development. Some growth 

 occasionally takes place on glucose agar. Gras is not formed in 

 glucose media. The vitality of cultures decreases rapidly on 

 any medium except milk. Even a whey-agar culture soon dies 

 out. There is little or no growth below 37 C. The optimum 

 temperature appears to be about 42 to 44 C. By growing 

 cultures in a hydrogen atmosphere in Novy jars we found that 

 the organism grows anaerobically as well as aerobically." 



BACTERIUM SUBVISCORUM MIGULA. 



Synonyms. Bacillus lactis viscosus Adametz. 



Place in nature. This organism was discovered by 

 Adametz l to be the cause of a ropy condition of milk and 

 cream. It is found in surface water. This organism is of 

 considerable interest on account of the peculiar and objec- 

 tionable condition it produces in milk. 



Morphology. There is a great variation in size depend- 

 ing upon the medium and age of the culture. On an agar 

 slant culture eight days old the spherical forms vary from 0.6 

 to 0.8 ft in diameter, while the elongated forms which pre- 

 1 Adametz. Landwirtsch. Jahrbiicher, 1891, p. 185. 



