52 EXCISION OF A LARGE MELANOTIC TUMOUR IN A MARE. 
I continued the dissection from below upwards to the left, and 
then towards the superior part, where I was forced to leave some 
portions affixed to the bones. I then endeavoured to lower the 
mass, in order to terminate the incision. This portion of the opera- 
tion was far from being the most difficult : the mass had now become 
more moveable and more easily displaced; and, besides, in operations 
on the tumour were no longer impeded by the tail. I was enabled to 
depress the soft parts, which yielded to the strong pressure which I 
exercised while bearing upon the tumour. After having freed the 
posterior extremity of the tumour by dissection, I took hold of and 
reversed it, but then I found that the action of my bistoury was im- 
peded. I substituted a strong flattened hook for the airigne, in 
such a manner as to be enabled to depress the mass and thus con- 
tinue the dissection, and was successful. I finished the incision 
by the dissection of the posterior part of the righi side of the tu- 
mour. The operation was terminated by my taking off, either with 
scissors or a bistoury, those portions of the mass which I had de- 
tached from the tumour during the process of dissection. I then 
plugged up the wound with dry tow, which was kept in its place 
by a suture of lint. Some slight hemorrhage took place, but this 
was stopped at once by the tow. 
I had only recourse to torsion, in order to close two arteries of 
about the size of a crow-quill. Notwithstanding the adherence of 
the tumour to the sub-sacral region, I was enabled to avoid the 
principal part of the arteries which abound there ; I should not, 
however, have succeeded in this, had I not preferred leaving 
some parts of the mass in different places, instead of dissecting them 
out cleanly at once ; and when once the chief part of it was got 
away, it was easy to cut off these portions without injury to the 
sub- sacral vessel. 
Had my object merely been the excision of the tumour, if 1 had 
not had to avoid the rectum and peritoneum, it would have been 
easy for me to have commenced the dissection at the upper part of 
the mass and continued it downwards, for the tumour would have 
been displaced, and drawn downwards without difficulty : but I 
thought it most prudent to avoid all risk of cutting the intestine, 
even though, in order to do so, I was compelled to go a roundabout 
way to work. Circular dissection certainly has its advantage, as 
it renders the latter part of the operation comparatively easy, and 
the tumour more moveable. 
I took off the dressings on the following morning, and placed 
fresh pledgets of tow. This was repeated every day for a week, 
after which the wound was left naked. At the expiration of five- 
and-twenty days it was completely closed. The mare was har- 
nessed full ten days before the wound was fairly cicatrized. 
