50 BOARD OF AGRICULTURE. 



into irregular portions by numerous broad, yellowisli-white 

 lines. Tlic cut surface presents the same marljlcd appearance 

 as before, caused by the change in the interlobular tissue, which 

 is sometimes from one to two lines thick. With these, the red 

 intervening tissue contrasts strongly. From the surface there 

 flows a red serum. Tiie smaller bronchia, on close examina- 

 tion, do not present a trace of exudation, and, in the larger, 

 the mucous membrane is perfectly normal. As the ])roper 

 j)ulmonary tissue is only infiltrated with serum, we may force 

 the latter out, and then inflate the lung. Sometimes tliere are 

 ecchymoses or larger effusions of blood, but rarely hepatization 

 of the sul)stance of the lung, this being exceptional. 



The new material found in the interlobular tissue varies in 

 different parts. "Where it is in contact with the lobules it re- 

 sembles cellular tissue in process of formation. It cannot be 

 distinguished from that which forms in other inflammatory con- 

 ditions, in the neighborhood of organized parts. The portion of 

 new material farthest removed from the living tissue is fre- 

 quently not organized, and may form a caseous friable layer, 

 composed perhaps of distinct laminae. Under the microscope 

 it presents nothing characteristic. 



In many cases irregular portions of lung of various sizes are 

 partially or entirely separated, and afterwards become enclosed 

 in a sac several lines in thickness, composed of newly-formed 

 cellular tissue. This change simulates what we find in tuber- 

 cular disease, but in the latter the encysted, masses are much 

 smaller. The small masses, however, in both cases, may after 

 a time become calcarious, and thus be mistaken for each other. 

 The mass mentioned is not always completely detached, but is 

 sometimes retained in the cavity by a portion which still main- 

 tains an organic connection with the surrounding parts. The 

 masses, when removed, generally appear as if just separated, and 

 have undergone no gangrenous change. The interlobular ma- 

 terial and the pulmonary tissue may be easily distinguished on 

 the cut surface. The mass, however, in some very severe cases 

 docs become gangrenous. 



After the disease has reached an advanced stage, incomplete 

 restoration may take place, but large detached masses are not 

 absorbed as is shown by the examination of animals in v/hich 

 they have been found as large as one, two, or three fists, a 



