LAMENESS IN HORSES. 
659 
its nature to cartilage : concentric layers of that substance are 
found lining the inside ; and in the course of time the cartilage 
changes, perhaps, to bone. At least, such are the transformations 
which in windgalls of the fetlocks of very long standing, under the 
protracted aggravation of work, are very apt to take place. Our 
departed friend, Mr. King, veterinary surgeon of Stanmore, in his 
lifetime, shewed us a beautiful specimen of ossified windgall. The 
tumour, which consisted of disease of the bursa lodged between 
the perforans tendon and the fetlock joint, in many places exhibited 
osseous patches; and it interfered, from its situation, so much 
with action, that the animal, incapable of extending his fetlock, 
was compelled, in going, to tread solely upon the toe. 
Notwithstanding these augmentations of substance and changes 
of structure the windgall, of the fetlock in particular, in many 
instances experiences, and notwithstanding the proportionate dimi- 
nution that, in consequence of the depositions taking place in- 
wardly, the cavit}' of the tumour necessarily undergoes, yet does 
not this cavity ordinarily become filled up and obliterated, but 
continues, greatly reduced of course in dimension, to exist and to 
contain fluid. This fluid may be but the natural secretion height- 
ened in colour and thickened in consistence ; on the other hand, 
when the tumours experience a repetition of injury from continued 
stress and strain upon them, coagula of blood are frequently found 
mingled with the secretion, exhibiting together that grumous cha- 
racter Gibson called “ corrupt jelly.” In windgalls that have be- 
come not only solid, but firm and hard to the feel, from their long 
duration and chronic character, is sometimes found, according to 
Hurtrel d’Arboval, a white chalky matter (semblable a du platre), 
though, according to him, this only occurs in cases in which the 
joints and tendons have become stiff. 
Our esteemed coadjutor, Leblanc, who has made these morbid 
changes his study, says, in giving an account of them, that he has 
observed the synovial membranes to lose their transparency and 
become variously clouded ; in the same articulation some portions 
of the membrane being of a vermilion red, while others exhibited 
a cherry red, a deep red, a yellow, and now and then a black 
aspect — such changes being particularly observable about the 
synovial fringes in the joint. Frequently, gelatiform infiltrations 
are observed underneath the membrane, within the fringes and the 
cellular tissue by which they are surrounded ; veritable false 
membranes of greater or less extent are likewise to be seen within 
the articular capsules. These membranes, adherent sometimes in 
places, at other times quite free, present great diversity of tinge 
and consistence : frequently they exhibit an analogy to the fibrine 
of agitated blood ; at another time they preserve the aspect of 
