374 Veterinary Medicine. 



later in many cases more or less necrotic and sloughing. In Dr. 

 Moore's experience this is more common on the conjunctiva 

 than on the nares or fauces. The interior of the eye was not in- 

 volved in the inflammation. Beneath the false membrane the 

 mucosa was devoid of epithelium and the underlying tissue was 

 red, raw and angry, bleeding readily when handled, and infiltrated 

 with an excess of lymphoid cells. 



The lesions, however, were by no means constant. In some 

 even of the fatal cases, the exudate was merely muco-purulent, 

 while in others the false membrane was quite abundant. 



The gravity of the affection also varies in different outbreaks 

 or in the same outbreak at different times. Sometimes it runs a 

 very rapid and fatal course, while at others it becomes chronic 

 and comparatively dormant and the great majority recover. 



In its more virulent form it is readily inoculable on birds, mice, 

 rats, and rabbits, while the milder cases are not easily propagated 

 in this way. 



The false membrane contains a variety of saprophytes, and 

 among them the pathogenic bacillus, which may be obtained in 

 pure culture by inoculating it on a rabbit or mouse. Emmerich 

 believed this bacillus to be identical with the Klebs-Iyoffler bacillus 

 of diphtheria in man, but lyofiier recognizes it as essentially 

 distinct. 



The bacillus diphtherim avium is 0.8 to 1.5^1 long, by 0.8 to 

 I.2/U, broad. The ends are oval so that short specimens seem 

 round. In bouillon cultures they form chains or clumps. They 

 stain in aniline dyes, most deeply at the poles. Are not stained 

 by Gram's method. They are non-motile, aerobic, grow in agar, 

 and alkaline bouillon, but render the latter acid in one or two 

 days. Do not grow on peptone gelatine, nor produce gas with 

 sugars. Are killed in 5 minutes at 58° C. ( 137° F. ) . Are killed 

 by dryness in 24^ hours, by sulphuric acid (0.25:100) in la 

 minutes, by lime water in i minute, and by sulphur fumes. 



Pathogenesis. Eight rabbits inoculated subcutaneously with 

 0.1 cc. of the bouillon culture died in 18 to 36 hours. Of several 

 white and gray mice inoculated only one died. Inoculations of 

 mature hens subcutem and on the nose had no effect. Inocula- 

 tion of a six weeks old chicken caused death in 4 days with ba- 

 cilli in the liver and blood (Moore). Inoculation of pigeons pro- 



