644 ANATOMY AND PHYSIOLOGY OF THE HORSe’s FOOT. 
not show the slightest trace of laminae, but was on the con- 
trary uneven, rough to the touch, and exhibited even more 
clearly than the outer face the fibrous framework of the 
horn. 
In eight or ten months, when the breach had been quite 
filled up, and the horn had extended as low as the ground 
border of the hoof, so that the wall cylinder was complete, it 
was noted that the whole mass of the interposed material was 
more prominent than that on each side, its outer surface was 
rugged, dry, destitute of the varnished-like appearance of a 
healthy hoof, and was furrowed longitudinally as well as 
transversely ; its inner face was only regularly formed in the 
cutigeral cavity, as beneath this the keraphyllse were entirely 
absent from above to below, and instead of the junction of 
the lower border of the wall with the sole in the ordinary 
manner, there existed a solution of continuity between these 
two. 
This experiment only demonstrated what is often met with 
in veterinary surgery, when, in consequence of injury 
or disease, the vascular laminse have been wholly or par- 
tially destroyed, altered in texture, or modified in function, 
and proved that, without the concurrence of the podophyllse, 
the coronary cushion alone could not produce a perfect wall 
as we are accustomed to see it in a healthy foot, and 
apparently cannot produce the horny laminse; whereas when 
the podophyllse are intact these are reproduced and with 
them the wall in an unaltered condition. 
It remains, therefore, to ascertain what share the vascular 
laminse take in the elaboration of the principal portion of the 
hoof, and in its maintenance in an efficient condition. Sur- 
gical experience and physiological experiment abundantly 
testify that they are incapable of secreting the wall when 
isolated from the coronary cushion. When a section of this 
wall is cut away from bottom to top, leaving the living 
tissues unprotected, though uninjured, we have seen that in 
a brief space they are covered with a corneous exudation so 
solid and consistent that there is no longer pain or incon- 
venience. But this exuded material, though exactly moulded 
on the living laminse, and therefore perfect with respect to its 
inner face, is remote from constituting even the basis of a 
complete wall, so far as the keraphyllse are concerned. 
Until the growth from the cushion has covered it, or pushed 
it downwards before it, this horny matter is only a pro- 
visional protection, which no doubt acquires a certain degree 
of thickness, and shows the keraphyllse much as they are in 
ordinary circumstances, but is otherwise notably different. 
