in the grey nasal secretion. The secretion decomposes and emits an offen- 

 sive odor. On the mucous membrane of the nostrils, small cancers form ; or 

 the whole nostril is completely filled with a firm, whitish-yellow cheese-like 

 mass, which frequently grows very rapidly and separates the nostrils and forces 

 the dorsal wall of the nostrils upward. This mass soon becomes dry and 

 brown on the outside ; and it adheres quite firmly to the mucous membrane. 

 If -it is- removed, it quickly forms again. 



Fig, 2.— A section through the deeper epithelial layer under a firmly attached false 

 menihrane. a. Swollen epithelial nuceli. b. Epithelial layers dislodged from 

 their normal position. c. Submucosa infiltrated by leucocytes. d. Homo- 

 geneous fibrinous exudate, e. Mixed fibrinous and purulent exudate. 



As the changes above described progress, it becomes impossible for the 

 bird to breathe through the nostrils, and the beak is kept open for breathing. 

 In the early stages of the catarrh, the irritation causes sneezing ; but later 

 this symptom disappears. 



Eyes. 



From the diseased mucous membrane of the nostrils, the inflammation easily 

 spreads to the mucous membrane of the mouth, pharynx, and larynx; yet, these 

 parts may be the first seat of the infection. When the disease afifects the eyes. 



