PATHOLOGY OF PULMONARY DISEASES OF THE HORSE. 
73 
making the parietes of the same inflexible, so that they lose their 
ability to contract or distend. The consequence is that the mass 
secreted by the bronchial mucosa stagnates and suffers many 
changes—condensation, tyrosis, etc. Bronchio-stenosis develops 
on account of the shrinking of the hyperplastic connective tissue. 
The transverse section of a bronchus which has been complicated 
by peri-bronchitis fibrosa, presents the appearance of a small? 
white ring, the opening of which is, by many, scarcely to be 
recognized, which is filled with a mucous-like tyrosie, or other 
mass. Those parts of the lungs which stand in connection with 
bronchi thus changed, cannot contain any more air; they retract 
and remain useless. A permanent atrophy, or chronic atelectasis 
of the pulmonary tissues, is developed. The atelectatic tissue is 
characterized by its desiccated state. The chronic inflammatory 
processes may extend from the peri-bronchial to the alveolar tis¬ 
sue, and generates an induration of the lungs. The size of the 
indurative nodus corresponds to the extension of the indurative 
process. A lobulis, or several noduli, may be complicated thereby. 
Around these nodes, which are often colored by the horse, is to be 
seen atelectatic tissue. 
Further, the pleura becomes sclerotic, and from the changed 
pleura we can follow fibrous threads, following the direction of the 
interlobular connective tissue in the lungs. This change hinders 
the extension of the parts of the lungs thus complicated, and 
causes shrinking of the same. 
In other cases a chronic pneumonia develops (carnification), in 
which the alveola also participate, and the lung becomes com¬ 
pletely impassable. This chronic pneumonia is by no means sel¬ 
dom by the horse, and leads to the formation of noduli of a white 
color and variable size, which may be easily complicated with 
those of malleus. Buhl designates this change as “ pulmonary 
cirrhosis.” 
This slight contribution to the pathology of pulmonary dis¬ 
ease is based on long-continued autopsie studies of my own—the 
results of which this is only a skeleton—which 1 have endeavored 
to place before my readers in a practical scientific form. The 
question of malleus I have only touched, where it seemed abso- 
