DISEASES OF THE OX AND SHEEP. 229 



it through the milk of the mother or nurse, if either be tuber- 

 culous. We should most stringently prohibit the use of milk 

 taken from tuberculous cows, and especially should the greatest 

 care be taken that infants should not be supplied with milk from 

 either mother, nurse, or cow, if suffering from the insidious 

 malady known as tuberculosis. 



The marrow, especially the red marrow, of bones, bears 

 an intimate relation to the blood, being, in fact, the chief source 

 from which the red blood discs are derived. In many constitu- 

 tional diseases the marrow of bones becomes seriously impli- 

 cated. Dr. Klein and Mr. Lingard examined the red marrow 

 at the end of the tibia and femur of a number of guinea-pigs 

 which had been inoculated either with human or bovine tuber- 

 cular matter, and they found that it is in the marrow that the 

 earliest manifestations of induced general tuberculosis are to be 

 detected. As early as fourteen days after inoculation, the 

 marrow of the tibia and femur was in all cases found to 

 contain small irregular yellow spots, vrhich were seen by the 

 microscope to be tubercles in the stage of caseation, tubercle 

 bacilli being present in them singly, in pairs, or in aggregates 

 of three or more together. Hence it is seen that the marrow 

 of long bones is the first tissue which becomes the seat of 

 the general infection in cases of induced tuberculosis. Moreover, 

 a large number of guinea-pigs having been inoculated in the 

 usual way with such marrow crushed and distributed in well- 

 boiled salt solution, all of them became affected with general 

 tuberculosis. 



Muscles taken from all parts of the bodies of animals affected 

 with general tuberculosis in various advanced stages were 

 examined, and they were found to be free from tubercle and 

 tubercle-bacilli, with the exception of those muscles which were 

 in close proximity to the seat of inoculation. 



Subcutaneous inoculation of guinea-pigs with tubercle leads 

 to the enlargement and caseation of the nearest lymph-glands, 

 and then to the purulent disintegration of them, whereby an 

 open discharging sore and abscess is established at or near the 

 seat of inoculation. This may occur after a few weeks or more. 

 Now it was only those muscles which were situated immediately 

 around these abscesses which were invaded with tubercle-bacilli; 

 in fact this muscular tissue had become generally involved in 



