IT. S. VETERINARY MEDICAL ASSOCIATION. 
453 
hind feet differ slightly, the former always approaching more to the type of the 
flat foot, while the hind ones resemble more those of the high-heeled foot. 
For the purpose of this paper, the physiology of the foot may be reduced to 
the recognition of a solid bony centre (second and third phalanx and navicular 
bone) with elastic lateral wings (lateral fibro-cartilages) surrounded by a vascu¬ 
lar network admitting of moderate movement (rete processigerum, rete plantarum, 
and synovials of the flexor tendons) which rest on an elastic cushion, and are en¬ 
veloped in a dense keratogenous box (wall, sole and frog) which plays only a 
passive part in the functional activity of the whole. The internal parts are rich 
in nutrient blood-vessels, and are luxuriant in nerves (tactile, general sensation 
and trophic). 
The keratogenous covering should be dense and firm, to resist friction, and 
moist and pliable, to accommodate itself to alterations of pressure. 
The elasticity and distensibility of the horse’s foot was recognized by Soiley- 
sel, and was made the object of special study by Bracy-Clark, Coleman, Geoag 
and Bouley, all of whom left information of value. 
Professor J. Lechner, of Vienna,* was one of the leaders in the study of the 
relative movements of the various parts of the foot, and he formulated a theory 
that, when pressure is placed on the foot from above, there is a dilatation of the 
coronary portion with a retraction of the plantar edge of the heels, producing a 
rotation of the posterior extremity of the walls. Professor Lechner employed 
in his experiments several instruments, one of the most ingenious of which was 
an electric current and bell. (Fig. 1). A rod (a) fastened to the toe of the 
Fig-1- horse’s foot, as this is the most fixed point, follows the line 
of the wall to the heel and holds a pin ( b ) which can be 
screwed in and out; the latter faces a piece of zinc set in 
the quarter ( e ); from the pin and zinc (b and c) wires 
(dd), extend to a bell. When weight is placed on the 
foot and the heels expand, communication is estab¬ 
lished between zinc and pin, and, the current connected, 
notice is given of it by the bell. The amount of expan¬ 
sion could be determined by a graduation on the pin. 
Professor Lechner’s paper elicited considerable contro¬ 
versy, and his work was followed by numerous experi¬ 
ments and studies by others. 
• Lungwitz and Schaaf, by means of an ectasimeter of their own, arrived at 
the following conclusions: 
1st. The raised foot is smaller at the plantar surface than it is when upon 
the ground. 
2d. Dilatation of the plantar border augments with the velocity of the 
gait. 
3d. The inside heel dilates more than the outside one. 
4th. The heels of the hind feet dilate less than those of the fore feet in the 
same horse. 
5th. The coronary band dilates at the same time as the plantar border. 
6th. Healthy or diseased feet dilate above, under pressure. 
*Net>er Hufrotation. Vortrag gehalten in der Section XI (Veter inarkunde) der ver- 
sammlung deutscbe Naturforscher und iErtze zu Salzburg, 1881. 
