10 



liquefied ; and such cases appear but seldom, while the cheesy matter in the 

 nose, as well as under the skin, shows no inclination to become so. They, 

 therefore, remain where they were formed, and lead to chronic catarrh. Often 

 there is apparent recovery, so that for a few days or weeks, the clinical symp- 

 toms vanish. Then the catarrh again becomes manifest. These cases of ap- 

 parent recovery are very important, as birds in this condition spread the dis- 

 ease if put among healthy ones. The pseudo-membranes in the mouth and 

 pharynx may be of a very transitory nature. They appear first here, and 

 then there, and but seldom disappear permanently, so long as any of the other 



Fig. S. — Pigeon (No. fi) 13 flays after inoculation with culture of the Roup 

 bacillus, {B. cacisiimti) anrl two days before death. 



symptoms of roup are present. In some cases (hen 28), the pseudo-membranes 

 form again with great obstinacy in a certain spot. In these cases, poultrymen 

 describe the trouble as cancer of the mouth. In a few exceptional instances, 

 death occurs after a short sickness. Hen 9 died in this way after symptoms 

 of roup had been recognizable for only two days. This bird showed a strong, 

 hemorrhagic inflammation of the mucous membrane in the olfactory region, 

 as well as swollen vessels in the meninges. Usually, however, death does not 

 come until the disease has run for some time. The direct causes of death 

 are anaemia, suffocation, inability to take nourishment, inflammation of the 

 brain from the nose or eyes, invasion by decaying products of albuminoid sub- 

 stances, and intoxication with bacterial poisons. 



Pathological Anatomy. 



In addition to the pathologic-anatomical changes already cited in the clini- 

 cal account, the post-mortem examinations furnish other data. In diseased 

 hen 9, mentioned above, the nasal passages were completely closed by dry, 

 cbessy masses, without any apparent clinical symptom. The bird had been 

 sick two days and showed small bloody extravasations in the upper parts of 

 the nasal mucosa. The mucous membrane itself was verv much inflamed. 



