432 
CANCER IN HORSES. 
cavities, and the inner bony wall of the left orbit, were 
destroyed, and their places occupied by the morbid growth. 
Superiorly, the upper end of the tumour rested directly upon 
ihe anterior portion of the cerebral hemispheres ; the two lay 
in apposition without admixture of texture, but this part of 
the brain had undergone absorption, or compression possibly 
also, so as to contain the tumour in a depression correspond- 
ing closely in size and shape with the hollow seen in the larger 
valve of an oyster shell. The dura mater was perfect and 
free internally, its outer surface was attached to the tumour. 
Its left margin invested the eyeball and appendages, was 
continuous with the external fungoid growth seen during 
life, and extended about halfway down the outer wall of the 
maxillary sinus. Its right margin lay in contact with the 
right inner orbital wall, and passed down the corresponding 
facial sinuses ; these cavities, however, were not so completely 
occupied as those on the left side. Below, the tumour 
extended into the upper part of the posterior nasal opening, 
where it presented a softened appearance ; it then passed into 
the left side of the pharynx and involved the corresponding 
pterygoid muscles, the contiguous salivary and lymphatic 
glands, and encroached greatly on this side of the Eustachian 
cavity. Parts of the mass most subjected to pressure were of 
a dirty white, and in some places of a grayish colour ; portions 
lying free in the sinuses, again, were pink or flesh-coloured, 
and vascular. Taken as a whole, its general hue resembled 
that of a slightly decomposed brain. Its surface was nodu- 
lated ; its attached parts graduated more or less perceptibly 
into the contiguous bones, muscles, and membranes. The 
brain was the only adjacent part which was absorbed or com- 
pressed, without being structurally changed. Its consistence 
varied ; the superficial parts were mostly softer than a fresh 
healthy brain, the internal substance was more solid. An 
incision carried through in any direction showed much the 
same colours as appeared outside, and exposed occasionally 
diffused spots of extravasated blood, which extended to the 
surface. 
Judging from the general aspect, consistence, and other 
external and internal appearances presented by this mass, I 
at once recognised its striking resemblance to encephaloma 
as seen in the human being ; and an examination of its struc- 
ture by means of the microscope, soon convinced me that it 
was a true medullary or encephcdoid cancer, partaking in some 
parts of the hamatoid character. An exceedingly attenuated 
mesh of delicate fibrous tissue was detected in places, but not 
disposed so as to form a uniform or substantial framework. 
