186 AVIAN TUBERCULOSIS 
and firm to the touch. Frequently they are confluent. When single 
they vary from 1 to 10 mm. in diameter. They are usually sessile on 
the intestine but on the mesentery they are frequently peduncula- 
ted, varying from 2 to 5mm. in length. On section the young 
tubercles exhibit a grayish, glistening surface, but the more advanced 
nodules contain recognizable necrotic centers. In the larger tuber- 
cles on the intestines the necrotic centers frequently open into the 
lumen. 
Fig. 45. A PHOTOGRAPH OF A TUBERCULOUS MESENTERY OF A FOWL. THERE ARE A 
FEW SMALL TUBERCLES ON THE INTESTINE. 
