352 
W. BRTDEN. 
limb, not by reopening the sore, bat by inducing the diseases pecu¬ 
liar to it. 
On a limb predisposed to curb it might be impossible to pro¬ 
duce a spavin, while there are others again so well organized, 
that it would be impossible to produce any disease on them. A 
rare commodity, but one, it is to be hoped, we may see more of. 
Some growths of the hoof interfere with the circulation, either 
by crowding the secreting structure or otherwise injuring the 
sensitive tissues within, and cause such diseases as thrushes, 
corns, quarter-cracks, toe-cracks, seedy toe or quittor. Peripheral 
disturbances and pain may be induced; both react on the limb, 
either directly or by reflex action, causing imperfect or unsyminet- 
rical organization, which in turn tends to equivocal action or gaits, 
such as pacing, spring-halt, hitching, interfering, over-reaching, 
paddling or stumbling; to deformities,such as ringbones, spavins, 
splints, curbs or atrophy of some part; the column of bones be¬ 
coming distorted and changed from the changes in the muscles, 
tendons and ligaments. 
The development of a projecting bone-spavin appears to me to 
be somewhat analagous to the physiological development of pro¬ 
jecting apophyses, as described by Marey; one is normal, the other 
is abnormal; in one we find the insertion of an important muscle, 
tendon or ligament, while the other might result from the meta¬ 
tarsal flexor—although sound—doing more than its share of work 
on account of the incompetency or change in other parts; or 
from atrophy, it having become shortened so that at every step it 
is overstrained, the ligaments or subjacent tissues being also in¬ 
volved. 
In a similar way I will take the liberty to suggest an explana¬ 
tion of the peculiar movements in spring-halt, as when an important 
muscle becomes atrophied or changed so that its functions are 
not performed in harmony with the rest. 
Growth of the whole or any part of an animal, if arrested for a 
sufficient length of time between birth and maturity, can never 
be fully recovered, whereas, after maturity, a part may atrophy 
or degenerate and again be restored; it is important therefore, 
that we recognize the necessity of placing the young animal unde. 
