THE CENTRAL NERVOUS SYSTEM 375 
in the brain, an enteritis existing however. Another 
case concerned a pet Indian Shama I had at my home. 
He had been doing well and singing loudly, until one 
evening he was allowed to remain in a tobacco-smoke- 
filled room whereupon next morning he stopped eating 
and singing. Later that day the clonic form of con- 
vulsions appeared, growing worse for thirty-six hours or 
until death. At autopsy no food was found in the 
alimentary tract. The brain and cord were congested 
grossly, while minutely, perivascular hemorrhages and 
marked vacuolization and diffuseness of staining were 
found in ganglion cells of the bulb, pons, anterior spinal 
horns and in the pyramidal cells of the cerebellum. Hap- 
pening so promptly after exposure to tobacco smoke, 
when the bird was doing well, I venture to associate 
the two. 
Ataxia. 
Incoordination and ataxia are so often observed and 
under so many conditions that it is well nigh impossible in 
any individual case to give an adequate explanation 
before death. They are in all probability the expression 
of sickness and nothing more in the vast majority of 
instances. When they are observed in such cases as the 
tyromata of the cerebrum or in certain of the ungulates, 
they may mean something definite. In this latter order 
and to a less extent in carnivores, one frequently sees 
weakness and uncertainty of gait in the hind-quarters, the 
legs being usually coordinate but tending to give way 
under the weight of the body. 
From a study of veterinary literature and our own 
material it would seem that this may have many explana- 
tions. In the first place, it may simply indicate weakness 
expressing itself in the heaviest part of the body, the 
animal inclining its femora forward to assist in support- 
ing the heavy abdomen. It may be an expression of 
abdominal pain, the recti becoming rigid and the quadri- 
