1 84 BACTERIA 



gained admittance at the time of milking. Thus we have 

 (i) the milk itself affording an excellent medium and supply- 

 ing ideal pabulum for bacteria, (2) a more or less lengthened 

 railway journey or period of transit giving ample time for 

 multiplication, (3) the favourable temperature of summer 

 heat. We shall refer again to the rate of multiplication of 

 germs in milk. 



Lastly, many are the advantages given to bacteria when 

 milk has reached its commercial destination. In milk-shops 

 and in the home there are not a few risks to be added on to 

 the already imposing category. Water is occasionally, if 

 not frequently, added to milk to increase its volume. Such 

 water of itself will make its own contribution to the flora of 

 the milk, unless indeed, which is unlikely, the water has 

 been recently and thoroughly boiled before addition to 

 the milk. Again, it is impossible to suppose that in 

 small homes — perhaps of only one room — where the milk 

 stands for several hours, pollution is avoidable. From a 

 hundred different sources such milk runs the risk of being 

 polluted. 



Before proceeding, a word must be said respecting the 

 first milk which flows from the udder in the process of milk- 

 ing, and which is known as th.Q fore -fnilk. This portion of 

 the milk is always rich in bacterial life on account of the 

 fact that it has remained in the milk-ducts since the last 

 milking. However thorough the manipulation, there will 

 always be a residue remaining in the ducts, which will, and 

 does, afford a suitable nidus and incubator for organisms. 

 The latter obtain their entrance through the imperfectly 

 closed teat of the udder, and pass readily into the milk-duct, 

 sometimes even reaching the udder itself and setting up 

 inflammation {mastitis). Professor Russell states that he 

 has found 2800 germs in the fore-milk in a sample of which 

 the average was only 330 per cc. Schultz found 83,000 

 micro-organisms per cc. in the fore-milk, and only 9000 in 



