334 TUBERCULOSIS AS A TYPE OF BACTERIAL DISEASE 



Woodhead, and others in their evidence before the Koyal Commis- 

 sion, the organs, glands, and membranes are the common sites for 

 tubercle, not the muscles (or meat). 



The following table records the findings of Geddes, who in 1901- 

 1902 was sent by the American Grovernment to examine by means 

 of tuberculin some of the chief breeds of British dairy cattle.* 



Eliminating the tests on Guernsey and Jersey, the proportions of 

 reactions among the tests made in Great Britaia and Ireland were as 

 follow :— in 1901, 13-67 per cent. ; in 1902, 20-97 ; and for both years, 

 17"92. Hopkins examined 571 Shorthorns and found the percentage 

 of positive reaction was 23'0 as compared with Geddes's result of 



23-25.t 



Tuberculosis of the udder is comparatively rare. Out of 100 

 tuberculous cows not more than 3 or 4 have tuberculosis of the 

 udder (Bang). The disease occurs as a diffuse, slightly hard, enlarge- 

 ment, generally unaccompanied by fever or tenderness of the organ. 

 Usually only one quarter is attacked, and that generally a posterior 

 quarter. The gland lobules become hypertrophied, and the larger 

 milk-ducts contain yellowish caseous masses full of bacilli. As the 

 condition advances, there is a considerable increase of the inter- 

 lobular connective tissue (interstitial mastitis) of the nature of a 

 sclerosis, and firm tubercles of various sizes begin to appear. Con- 

 sequent upon these changes the udder becomes nodular, and hard 



* Nineteenth Annual Report of the Bureau of Animal Industry, 1902, p. 551. 

 ■\ Report of Minister of Agriculture, Dominion of Canada, 1902, p. 134. 



