346 SCIENCE PROGRESS. 



cular peritonitis, it must be remembered that the form of 

 tubercular peritonitis that occurs in children does not exist 

 in guinea-pigs, cattle, or pigs. It is present in horses. In 

 human tubercular peritonitis in some cases a local lesion is 

 found in the intestine ; in other cases there is no local 

 lesion ; the mesenteric glands are tuberculous, and the 

 chief seat of the disease is the peritoneum. It seems 

 very probable that in many cases of tubercular peritonitis 

 the affection is associated with the ingestion of a small dose 

 of the tubercular poison, although this is not so in all cases. 



Affection of parts of the body far removed from the 

 channel of infection (such, for example, as the bones, joints, 

 the epididymis, and the pia mater) is one of the most 

 interesting problems in tuberculosis ; since there is no direct 

 lymphatic connection between these parts, and from the 

 primary tubercular lesion infection must occur by means of 

 the vascular system. Thus in the human being tubercular 

 joint or bone disease, or infection of the epididymis or the pia 

 mater, may occur in a case which is evidently primary lung 

 tuberculosis, or primary intestinal tuberculosis. But there 

 are other cases in which the channel of infection is not so 

 evident. In some of these, indeed, a tubercular lesion in the 

 retrograde stage is present at the apex of one or other lung, 

 or in the intestine, or is shown in scrofulous glands below 

 the neck, or in tuberculosis of the mesenteric glands. These 

 small lesions are frequently overlooked in post-mortem 

 examinations, so that the cases are described as primary 

 tubercular meningitis, epididymitis, or bone, or joint disease. 

 In some cases, however, the primary local lesion cannot be 

 discovered, although it is more frequently not looked for, 

 and it is quite possible that in the tissues of children, which 

 are so active in absorption, the tubercle bacillus might enter 

 the blood stream directly without producing a local lesion, 

 and so be carried to a distant part, where it produces its 

 characteristic lesion. 



The exigencies of space preclude a further discussion ot 

 this part of the subject, and I will finish what I have to say 

 by considering briefly some of the sources of infection in 

 tuberculosis. If tuberculosis is a disease in which an 



