40 Williams, Fisher, and Udall: The Spavin Group. 
losed, and the destruction of motion be sufficiently effective to. 
cause a cessation of pain, but an accident or hard work may 
interrupt the anchylosing process and suddenly cause more or 
less severe lameness. 
In other cases, not very rare, the lameness, when appearing 
suddenly, can only be attributed to fracture, the bones having 
become so weakened that they break from ordinary use, as is 
seen in split phalanges and as might readily occur in the navic- 
ular bone in a case like Fig. XIX. In yet other cases, the 
lameness is due to the tearing away of the tendons from the 
softened bone. Finally there is a tendency in some of the larger 
joints, as at N?, Fig. VIII, to the calcification of the synovial 
fringes and their ultimate detachment and escape into the syno- 
vial cavity, where, floating freely, they may become engaged 
between the ends of the bones, causing sudden and extreme 
lameness until such time as the floating body may become dis- 
lodged. 
SYMPTOMS. 
The symptoms of this group of lamenesses are exceedingly 
varied and complicated. The advent of the affection is usually 
_ slow and insidious, but it may appear suddenly and pursue a 
rapid and violent course. In many cases ringbone and spavins 
[ appear in young animals so insidiously that even with two 
spavins and four well developed ringbones, there may be no 
lameness or stiffness to attract the attention of the owner, the 
animal may be thrifty, in good flesh and growing well, the 
exostoses attain their growth and become wholly quiescent and 
remain so, the animal performing ordinary work during its life- 
time without apparent difficulty of any kind, the exostoses hav- 
ing the simple value of blemishes. As a rule, it may be said 
that the younger the animal the less serious the exostoses and 
other lesions of which this may be the chief expression. In 
these cases where the owner observes no symptoms of lameness 
or difficulty of locomotion, it is not unlikely that the trained’ 
eye would note a peculiar stiffness of gait, a disinclination to 
run and play, a caution in locomotion, a “tied in” gait. Certain 
it is that in numerous cases of a very insidious type, in young 
and old animals alike, there is no distinct lameness, but for 
weeks or months, exceptionally for years, there is an ill defined 
soreness in the gait, not amounting to lameness, but abbreviating 
NOY AN, 
