232 DISEASES OF DOMESTICATED BIRDS 
sis eventually involves the wings and neck. Appetite remains good 
and there is no evidence of pain. Marx noted the presence of 
marked lachrymation in every case. Affected birds have been ob- 
served to live for seven months and no instance of complete recovery 
has been noted. Young birds are most commonly affected, but the 
disease may be encountered among those of any age. The disease oc- 
curs at irregular intervals in certain areas. 
Morbid anatomy. The one constant lesion as observed by Rob- 
ertson is the congestion or inflammation of the duodenum and the 
reddened appearance of the mucosa, accompanied by a deposit of 
exudate thereon. This lesion is present in some degree in all cases, 
whether early or of long standing. The sub-mucous layer of the in- 
testine is thickened and infiltrated with a clear straw colored fluid. 
Marx observed more or less peritonitis and purulent foci in the 
spleen in each case. In some cases there was enteritis with necrotic 
patches on the mucosa. 
Bacteriology. Robertson obtained from the inflamed mucosa, a 
short rod which does not stain by the Gram method. It grows fairly 
well on the common culture media under aerobic or anaerobic condi- 
tions. There is copious white growth on plain agar, glycerine agar, 
agar, gelatin and malachite green agar. On the latter the color is 
discharged along the needle track. Gas is evolved in sugar agar 
stab cultures. Growth occurs in plain bouillon, glycerine bouillon 
and sugar bouillon causing turbidity and foul odor. A brownish col- 
ored raised growth occurs on potato. Milk is not coagulated nor does 
liquefaction occur in gelatin. In natural cases, besides the organism 
in question, Staphylococcus pyogenes aureus almost invariably is pres- 
ent in cultures from the sub-mucosa of the duodenum. 
Marx isolated a non-motile, non-spore bearing, Gram negative, oval, 
bipolar staining rod, which is killed by exposure to 68° C. for an 
hour. It grows readily on the ordinary culture media. Coagulation 
of milk occurs, growth on gelatin resembles that of B. coli, and a 
brownish viscid layer is produced on potato. Glucose is fermented 
and no indol is produced. After 24 hours on agar there appear gray- 
ish white colonies, iridescent by transmitted light which eventually 
develop into a moist greenish white layer. Bouillon becomes turbid 
in a few hours and a deposit of sediment forms in the tube. Marx 
regards the organism as belonging to the hemorrhagic septicemia 
group. 
Pathogenicity. Subcutaneous injection of 25 cc. of a 24 hour 
culture of Robertson’s organism into a cock ostrich resulted in the 
