MELANOSIS. 
373 
Large Tumour . — Its inferior border runs from the fossae above 
and behind the outer canthus of the left eye, extending backwards 
over the superior part of the parotid gland, where it terminates 
abruptly. The tumour completely covers the zygomatic process 
and the maxillary articulation ; it is firmly fixed at its base — it is 
lobulated, and very little elastic, except in the central part. It 
measures seven inches from its anterior to its posterior ex- 
treme : it is not painful, neither is the temperature of it greater 
than any other part ; its presence, however, evidently impedes the 
free motion of the jaw in mastication, for mastication is performed 
very slowly, and the jaw is greatly limited in its action. 
Small Tumour . — The small tumour is situated at the supero- 
inferior part of the left side of the neck ; immediately behind the 
curve of the inferior maxilla, and between the bifurcation of the 
jugular vein. This tumour differs from the other in not being 
lobulated, and in allowing of a certain extent of motion when 
handled. The space between the tumours and the whole of the 
left side of the cheek and face down to the lips is swollen. 
I next examined the mouth, teeth, &c., but all were in a very 
healthy condition. The pulse beat 38 per minute, and the respi- 
ration was natural. I did not give a positive opinion as to the 
nature of the affection at this time ; but from the colour of the 
animal, AND FROM THE FACT OF THAT COLOUR HAVING CHANGED 
FROM dark TO LIGHT — from the age — from the manner in which 
the tumours commenced, and their gradual growth to the present 
time — and, lastly, from the absence of inflammation, I told the 
owner I believed the disease would prove to be melanosis. I re- 
frained from all treatment, with the exception of having the parts 
fomented twice or thrice daily until I saw the animal again. 
I did not see the case again until the 2d of July, when I found 
an alteration for the worse had evidently taken place. 
The larger tumour has increased in every direction ; it now ex- 
tends down the cheek, passes under the inferior maxilla, and fills 
the submaxillary space, and finally appears to terminate at the root 
of the ear on the right side of the head. The second tumour has 
also greatly increased in size, and, from its situation, it appears to 
press upon the larynx and superior portion of the trachea. The 
animal is worn to a mere skeleton, caused not so much from con- 
stitutional disease as from inability to masticate food. When the 
mare attempts to eat, the food is first gathered very slowly into 
the mouth; the head is then inclined to the right side, and main- 
tained in that position while she endeavours to masticate it, which 
appears to be entirely done by the molares of the right side: a 
similar difficulty occurs in swallowing the mass. The muscles on 
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