506 
DISEASED BRAIN OF A SHEEP. 
less injury to the skull, but I still hope that you will be 
enabled to make a satisfactory examination of it. 
I am, &c. 
To the Editors of the ‘ Veterinarian* 
[We are indebted to Assistant Professor Varnell for the 
following description of the pathology of the case and the 
changes that had taken place.] 
The partially decomposed state of the above specimen, as 
well as the injury it had received at the hands of the butcher, 
precluded the possibility of my forming an opinion of the 
nature of the disease under which the animal had laboured, 
with the same degree of correctness as I might have done 
had I seen the parts immediately upon the sheep being 
slaughtered. If, also, more facts relating to the symptoms, 
and other circumstances which were associated with this 
malady, had been furnished, I should have been better able 
to come to a conclusion as to the cause which gave rise to 
the affection, as well as of its true pathology. 
On exposing the cerebrum the right hemisphere was found 
to be alone affected, and this was carefully examined, as were 
also its membranes, and the optic nerve and its outer covering, 
from the base of the brain to its entrance into the globe 
of the eye. The eye itself was so much decomposed and 
broken up that no satisfactory examination could be made 
of it. 
Both the optic nerve and its outer covering were, however, 
found to be free from disease. 
The dura mater, and the parietal as well as the visceral reflec¬ 
tions of the arachnoid membrane, appeared to be natural, as 
was also the pia mater, with the exception of its larger vessels 
which evidently contained more blood than usual. The 
veins, also, of the choroid plexus and of the velum inter- 
positum were slightly distended with blood, and had, with 
the parts before alluded to, a rusty appearance. 
Between the visceral and the parietal reflection of the 
arachnoid membrane a layer of lymph was located, which, at 
the base of the brain, was much thicker than at any other 
part, and was here undergoing the process of degeneration 
into pus. 
The general condition of the parts would lead to the 
inference that water had existed, at the time the sheep was 
slaughtered, both in the arachnoid space and also in the 
ventricles of the brain, and that it had escaped when the 
