102 SCIENCE AND PRACTICE OF DAIRYING. 



of the caseous matter, and subsequently redissolves a portion of the 

 coagulated mass, leaving in addition in the milk the unpleasant 

 flavour of herring-pickle (trimethylamine). Bacteria lactis ery- 

 throgenes coagulates the milk and imparts to it, if light be excluded, 

 a uniform blood-red colour; and a kind of sarcina produces a 

 brown-red colour in the milk. 



In feeding with milk which is infected with colour-producing 

 bacteria, no deleterious action has yet been observed to be produced. 

 Such bacteria seem, therefore, not to exert a deleterious action on 

 the animal body. It is obvious that all the influences due to 

 fission fungi, which exert a disturbing effect on dairy practice, can 

 be imparted by means of the organisms and the spores from one 

 mass of milk to another, that is to say, they are infectious. For this 

 reason, the only way of curing them where they exist is by the 

 destruction of the respective fission fungi. 



It is often very difficult to remove effectively the disease germs 

 present in milk, since the conditions of breeding favourable to the 

 organisms in the milk are not known, and also because almost 

 nothing is known of the development of the individual fission fungi. 



43. Micro-organisms in Cheese. That the ripening of cheese is 

 connected with and influenced by micro-organisms, and is successful 

 or the reverse, according to the nature of the organisms that are pre- 

 sent in predominating amount, is beyond doubt. Since it has been 

 proved that the organisms which are present in the cheese from the 

 first are largely developed during the ripening period, and since the 

 ripening will not take place when certain substances which are fatal 

 to germ-life are introduced, although these may not have any in- 

 fluence on the albuminoids of milk, or when fresh cheese is protected 

 from the action of air, it follows that it is the low micro-organisms 

 which effect the ripening in all cheese. Since all the different kinds 

 of micro-organisms produce definite effects, it further follows that 

 each individual cheese requires for its ripening a special kind of 

 micro-organism. As our knowledge of the use of different kinds of 

 micro-organisms for producing the many different kinds of cheeses, 

 and without which the specially desired effects of the ripening are 

 not obtainable increases, the great uncertainty which at present 

 prevails in the manufacture of cheese will gradually vanish. But 

 the application of a knowledge of the specific action of the various 

 micro-organisms to the manufacture of cheeses is not easy, and we 

 can scarcely hope to see it soon successfully effected. The subject is 



