274 BACTERIOLOGY. 



as the liver and peritoneum, contains large numbers 

 of tubercle bacilli. If smaller doses are given the 

 disease is prolonged. The peritoneum and interior or- 

 gans spleen, liver, etc. are then filled with tubercles. 

 On subcutaneous injection, for instance, into the ab- 

 dominal wall, there is a thickening of the tissues about 

 the point of inoculation, which breaks down in about a 

 week and leaves a sluggish ulcer covered with cheesy 

 material. The neighboring lymph-glands are swollen, 

 and at the end of two or three weeks may attain the 

 size of hazel-nuts. Soon an irregular fever is set up, 

 and the animal becomes emaciated, usually dying within 

 four to eight weeks. If the injected material contained 

 only a small number of bacilli the wound at the point 

 of inoculation may heal up and death be postponed for 

 a long time. On autopsy the lymphatic glands are 

 found to have undergone cheesy degeneration ; the 

 spleen is very much enlarged, and throughout its sub- 

 stance, which is colored dark red, are distributed masses 

 of nodules. The liver is also enormously increased in 

 size, streaked brown and yellow, and the lungs are filled 

 with grayish-white tubercles; but, as a rule, the kidneys 

 contain no nodules. Tubercle bacilli are always found 

 in the affected tissues, but the more chronic the process 

 the fewer the bacilli that are apt to be present. 



Rabbits are also quite susceptible to tuberculosis, but 

 considerably less so than guinea-pigs. In rabbits death 

 almost invariably follows inoculations of tuberculous 

 material into the anterior chamber of the eye. The 

 local effects are iris-tuberculosis and cheesy degeneration 

 of the pupil. The bacilli then penetrate to the neigh- 

 boring lymph-glands, producing softening of these, then 

 pulmonary tuberculosis, general tuberculosis, and finally 



