MOKKID ANATOMY 



493 



From the observations thus far made the provisonal 

 theory is entertained that the three forms of the exudate— 

 serous or muco-purulent, diphtheritic and sloughed mass- 

 represent three stages in the course of the same disease. It is 

 easily understood that fowls examined in the first stage would 

 be said to be affected with a catarrhal condition of the mucosae 

 of the eyes or nares. It is highly probable that in many cases 

 the disease never reaches the second stage and if these cases 

 alone were examined the diphtheritic condition would not be 



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Fig. ii8. Diphtheritic exu- 

 date in the larynx of a fowl : 

 (a) the grayish-white exudate 

 projecting from the glottis. 



Fig. 119. A longitudinal sec- 

 tion through the larynx and 

 trachea ofafnvl {same as iiS) , 

 showing the exudate: {a) in the 

 larynx and (b) in the trachea. 



suspected. It appears, however, that in the majority of cases 

 the disease runs its course and membranes are formed, slough 

 and recovery follows. It is furthermore presumable that the 

 disease in que.stion appears sometimes in a virulent and de- 

 structive form. I am in possession of statements from poultry 

 raisers which show that there are occasionally epizootics of a 

 disease characterized by exudates in the eyes, nose or mouth, 



