tumours, while the mucous membrane of the mouth remained apparently nor- 

 mal. These tumours enclosed the above-mentioned cheese-like masses. 



The pseudo-membranes in the mouth may appear in a third way, which 

 usually happens in more severe types of the disease. The Cella inira-orbitahs 

 becomes distended on all sides by the secretion retained in it. For this rea- 

 son, it presses the palate towards the mouth-cavity. The palate, therefore, 

 may thus attain twice and three times its regular breadth (as in fowls 5 and 27). 

 Where the pressure is strongest, the bone stratum becomes absorbed, and a 

 typical pseudo-membrane forms. This latter may easily be removed ; and if 

 left it communicates directly with the firm cheese mass in the infra-orbital cavity. 



Fig. 4. — Section through a finnly atlai-hed false inenibraiif from lieii 

 No. 17. a An altered epitiielial niiolens not i|uite in focus, and 

 consequently, not siiarply outlined. c. Nuclei of the leucocytes. 

 d. Granular detritus. e. A number of bacteria in the middle of 

 an homogeneous fibrinous exudate. 



!n fowls 14 and 17. in addition to diphtheritic membranes on the mouth 

 near the angle of the beak and at the nostrils, tumors were formed on the 

 skin. These grew to the size of a pin head, or the pit of a cherry. Th'e 

 feathers on the tumours fell out. and the skin beneath was found to be cover- 

 ed with grey scales. The tumours were in direct connection with the pseudo- 

 membranes on the mucous membranes, and formed a grey, dry, crumbly mass. 



While in the cases under observation, the region around the larynx was 

 very often the seat of croup-membranes, the disease never passed into the 

 larynx or the trachea. Yet. according to the statements of many others, these 

 organs are favorite places for the development of pseudo-membranes in the 

 course of American Fowl Diphtheria. 



Severe pneumonic dispnoea appeared in fowls i. 6. 12. 18, and 19. The 

 thoracic walls were used for inspiration and expiration. The beak and larynx 

 were always kept open. The visible mucous membranes, the crest, and the 

 wattles became cyanotic. The dispnoea grew worse and worse, and led to 

 sufifocation in i to 4 days. 



