1 8 MILK AND THE PUBLIC HEALTH CHAP. 



Ward, 1 in a more recent publication, gives an account of 

 further experiments. The udders of 19 milch cows from five 

 different dairies were examined. All the cows were tuber- 

 culous, but in no case was the udder tuberculous or abnormal 

 in appearance. He found that the lactiferous ducts of the 



19 udders examined harboured bacteria throughout their 

 whole extent. A number of different kinds of bacteria were 

 isolated, the majority being micrococci. Ward also carefully 

 studied the anatomy of the udder, and concluded that no 

 obstruction capable of excluding bacteria from the milk-cistern 

 exists, except perhaps the sphincter muscle at the lower end 

 of the teat. He further concluded that there was no obstacle 

 to prevent bacteria finding their way through the fine ramifica- 

 tions of the lactiferous ducts to regions remote from the teat. 



Uhlmann 2 showed the presence of numerous bacteria in 

 sections of the hardened teats of cows, goats, and sheep. 



Henderson 3 examined seven normal udders and found that 

 76 per cent of the cultures made exhibited growths of bacteria. 

 Staphylococci, streptococci and pseudo- diphtheria bacilli were 

 isolated. All were non-pathogenic. It is interesting to note 

 that two of the normal udders were taken from young heifers 

 and were unexpanded, and all the cultures made from the milk 

 cistern, ducts, and parenchyma, remained sterile. 



That milk as delivered from the teats even when obtained 

 with aseptic precautions, and after rejection of the fore milk, 

 contains bacteria, has been demonstrated by numerous in- 

 vestigators. The fore milk contains most of the bacteria, 

 but the middle milk and strippings are also bacterially con- 

 taminated. For example, von Freudenreich 4 had 28 cows 

 milked, with careful precautions to avoid outside contamination, 

 into sterile flasks. The mean bacterial content for each cow was 

 230 per c.c., the number of bacteria varying from 65 to 680. 



Lux 5 examined 260 specimens of cows' milk and 9 5 from 

 goats, the samples being collected direct from individual cows 

 but without special antiseptic precautions. He found, on an 

 average, 1395 bacteria per c.c. 



1 Bulletin No. 178, Cornell University Agric. Experiment Station, 1900. 



2 Inaugural Dissertation, 1903. 



3 Journ. Roy. San. Inst., 1904, xxv. p. 563. 



4 Centralbl.f. Bakt., 1902, Abt. II. viii. p. 674. 



5 Centralbl.f. BaTct., 1903, Abt. II. xi. p. 273. 



