163 



(3) The blocking of the blood vessels gives rise to ischaemic necrosis 



(Cohnheim), in which all stages of necrobiosis, demarcation, and 

 of incipient regeneration can be demonstrated. 



(4) The dead portion can undergo sequestration, a capsule of con- 



nective nature being formed by reactive inflammation (lungs, 

 muscles), or the primary pleuro-pneumonia process comes to 

 a standstill, and the tissue become transformed into a cicatrice 

 by opposition of connective tissue (subcutaneous tissue). 



(5) The lesions of pleuro-pneumonia having originated by metastasis 



present microscopically the image of a corpuscular infiltration 

 with pronounced serofibrinous exudation, without there being 

 any localisation of the process within definite portions of the 

 tissue. It is in the nature of the virus to form metastases, 

 especially in the joints, the age of the affected animal being 

 apparently immaterial. 



(6) The histological lesions around the vessels differ from those of 



chronic productive pneumonias, and can be used with certainty 

 for diagnosis. 



