84 
OSSEOUS TUMOUR REMOVED FROM THE STIFLE- 
JOINT.—ITS TRUE NATURE? 
By Mr. Lamb, First-Class Veterinary Surgeon, Kirkee, 
Bombay Presidency. 
In the Veterinarian for December, 1862 (p. 774), is an 
account of an ossific tumour removed from the back of a 
mare by Mr. Longman, V.S., 9th Lancers, upon which Pro¬ 
fessor Varnell remarks that the tumour must not be consi¬ 
dered as true bone, which, from its hardness and weight, it 
might be taken for, because, unlike true bone, it is wholly 
destitute of the Haversian system of canals for the passage 
of blood-vessels. 
I have the pleasure to enclose you herewith a thin section 
of a similar though much larger tumour, upon the nature of 
which I should be glad to have your opinion, for to me it 
appears, under the microscope, to have the Haversian system 
of canals, &c., remarkably well developed, at least in some 
parts, if not in all. 
The tumour was situated over the off stifle-joint of troop- 
horse “ No. 33, B Battery, 4th Royal Horse Brigade.” I 
believe it had been under observation for about two years, in 
which time it had gradually increased from the size of a 
hazel-nut to its present dimensions. I removed it on the 
23rd of February last. It was intimately connected with the 
skin, from which I dissected it carefully, dividing, however, 
three tolerably large arteries, which had to be secured. It 
was very loosely connected to the bones of the stifle- 
joint by cellular tissue. Immediately after excision it 
weighed 1 lb. 11 oz. avoirdupois. The surrounding cartila¬ 
ginous mass being removed, it presented an appearance very 
like a petrified sponge, and measured ten and three quarter 
inches in circumference lengthwise, and nine inches trans¬ 
versely. I cannot ascertain, nor can I suggest, any cause for 
the formation of this tumour. 
[We felt satisfied, by an ordinary inspection only of the 
section sent by Mr. Lamb, that the tumour from which it 
had been taken was essentially of a bony nature, but still it 
became necessary to prepare a portion of it for microscopical 
examination. On this being done, all the well-known cha¬ 
racters of bone were distinctly observable, the Haversian 
canals, lacunae, canaliculi, &c., being as perfectly arranged 
as is usually the case in all adventitious bony tumours.] 
