602 ANATOMY AND PHYSIOLOGY OF THE HORSE’S FOOT. 
applied ; so that if the sole and wall be seized in a pair of 
pincers and gently squeezed, the jet increases in force and 
rapidity coincidently with the application and degree of 
pressure, and slackens again when it is removed. The same 
phenomenon is observed when the horse paws with the 
wounded foot. 
In addition to the salutary pressure exercised at each step 
by the bones and hoof on the membranes which sustain this 
venous system, the elasticity of various parts of the foot and 
hoof, brought into play by the movements and weight of the 
animal, also greatly assists in accelerating the circulation in 
this organ ; the almost incessant dilatations and contractions 
of these parts supplementing to a larger extent than is, per- 
haps, generally imagined, the systolic and diastolic action 
of the heart, whose influence, though doubtless still in ope- 
ration, must, nevertheless, be greatly diminished at such a 
distance. 
This accession of force to the venous circulation should be 
most notable within the concavity of the very elastic lateral 
cartilages, where the convolutions and reticulations of these 
vessels are most numerous, dense, and close. 
That the mechanical effects of movement and pressure 
most powerfully influence the flow of blood in the foot, 
is evidenced by the result of compelling horses labouring 
under congestion, or, perhaps, even inflammation of the 
laminse, to walk about. However lame and unwilling these 
animals may be to travel at first, owing to the extreme 
pain they suffer, yet owing to the relief afforded by the quick- 
ened motion, which empties the over-distended vessels, allows 
them to regain their normal dimensions, and also enables 
them to carry on the diminished stream of blood that follows 
after the congested state, progression becomes easier, and is 
finally accomplished with tolerable freedom. In this way, 
what is usually termed “ laminitis,” but which, in many 
cases, is only congestion of the laminse, can be frequently 
cured in a very short time ; while the actual disease may be 
in its early and, perhaps, even later stages benefited — results 
which are usually attributed to other means. 
A knowledge of the advantage to be derived from the alter- 
nate pressure and relaxation of the vascular membranes of the 
foot, induces us to recommend that horses should be gently 
led about in hand for some time after a long and fatiguing 
journey, in order to allow the pedal circulation to become re- 
established, and to accommodate itself to the lessened demands 
of inactivity. Allowing immediate relaxation and rest after 
severe exercise is a very likely means of inducing congestion 
