330 DIPHTHERIA IN FOWLS 



tissue from the cornea and the mouth, show that there is a cell 

 infiltration into the mucosa which destroys the epithelial layer 

 and frequently the submucous tissues to a considerable depth. 

 See Plate YIU. 



The fact should not be overlooked that the disease in the 

 eye is usually confined to the conjunctiva and the cornea, the 

 posterior portion remaining apparently normal. 



From the observations thus far made the provisional 

 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 mucosa 

 of the eyes or nares. It is liighly 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 

 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 further presumable that the disease 

 in question appears sometimes in a virulent and destructive 

 form. I am in possession of statements from poultry raisers 

 which show that there are occasional!}' epizootics of a disease 

 characterized bj- exudates in the eyes, nose or mouth, which 

 runs a rapidly fatal course. It appears that it is such out- 

 breaks which have been reported in Europe as diphtheria and 

 not the low form of chronic disease which has been studied in 

 this country. 



§ 249. Relation of diphtheria in man to that in fowls. 

 A comparison of the bacillus of diphtheria in man ( Klebs- 

 Loeffler) with those described from diphtheria in fowls, shows 

 that morphologically and in their pathogenesis for experi- 

 mental animals the organisms are in no way alike. There is 

 also a marked difference in the nature of the exudate in fowls 

 and in man. The non-identity of these diseases has been 

 clearly pointed out by Menard*. Although these maladies are 

 shown by several observations to be unlike in their etiology 

 and the character of their lesions, the transmission of fowl 



*Revue d'Hygiene. Tome XII. ( iSgo), p. 410. 



