DISEASES OF POOIvTRY. 



211 



friable than in health, and ruptures leading to fatal 

 hemorrhages may occur. 



The peritoneum, or serous membrane of the 



abdominal cavity, may be covered with tubercles the 



size of a pin head or smaller; and when this occurs 



the abdomen usually contains more or less liquid. 



The intestinal walls are often thickened or ulcerated, 



and contain tuber- 

 cles of various 

 sizes. Sometimes 

 these are so large 

 that they diminish 

 the caliber of the 

 tube or entirely ob - 

 struct it. The soft- 

 ening and breaking 

 down of the tuber- 

 cles on the inner 

 surface of the in- 

 testine cause the 

 ulcerations which 

 are commonly seen in this disease, and from which 

 the bacilli escape in incalculable numbers. 



The abdominal lymphatic glands may be invaded 

 by the tubercular process and enlarged to the size of 

 an egg. 



Small tubercles, the size of a pin head or less, and 

 sometimes larger tubercular masses, are occasionally 

 found in the lungs, air-sacs, heart and pericardium, 

 but these organs are more rarely affected than are 

 those situated in the abdominal region. 



Generalized tuberculosis is not uncommon and in 

 this form of the disease most or all of the organs of 



Fig". 62. — Tubercular tumor of the head. 



