INFECTIOUS DISEASES OF CANARY BIRDS 253 
forms. Bouillon becomes slightly clouded and abundant sediment 
accumulates. Milk is not coagulated and no gas is formed in sugar 
agar. Gelatin is not liquefied. Blue colonies form on Drigalski 
plates. A trace of indol was observed by one writer. 
Several writers who have worked with the organism regard it 
as a member of the hemorrhagic septicemia group. Miessner and 
Schern name the organism Bacillus canariensis necrophorus. 
Pathogenicity. The organism induces disease in canaries when 
introduced subcutaneously and per os. The disease must progress 
for at least three days in inoculated birds before the characteristic 
necrotic lesions develop. Mice, sparrows, finches, guinea pigs and 
rabbits are also susceptible. Pigeons vary in susceptibility while 
hens are resistant. 
Symptoms. There is nothing characteristic about the behavior 
of birds harboring this infection. The birds lose appetite, become 
less lively and finally squat in a corner of the cage. Death occurs 
after a sickness of from 24 to 36 hours. 
Morbid anatomy. The characteristic feature observed at 
autopsy is the presence of metastatic foci in the spleen, liver and 
occasionally in other organs. 
The liver is enlarged and contains numerous yellow foci the size 
of a pinhead and larger as seen by the unaided eye. The use of a 
hand lens reveals smaller punctiform foci. These areas present a 
great variety of shapes, and do not separate readily from the sur- 
rounding tissue. They are sometimes leathery in texture, some- 
times crumbly in structure. The larger ones when cut, are seen to 
consist of a homogeneous central mass surrounded by an opaque, 
gray colored zone. 
The spleen is swollen into a cylindrical form and contains similar 
nodules. These distend the capsule and cause the surface of the 
organ to have an irregular, undulating appearance. The spleen 
contains so many nodules and is so fragile in consequence, that it 
breaks apart when grasped with tweezers. The mucous membrane 
of the pharynx occasionally contains yellowish nodules’ which may 
be detached with the tweezers. The walls of the pleural cavities oc- 
casionally are covered with yellowish exudate, and the lungs may be 
involved. Intestinal inflammation is sometimes observed. 
The necrotic lesions closely resemble those of avian tuberculosis, 
but tubercle bacilli are not demonstrable. 
Stained sections of the nodules in the organs reveal the fact that 
the smaller ones consist of great clumps of bacteria which have 
