146 ANATOMY AND PHYSIOLOGY OF THE HORSE’S FOOT. 
iiave mentioned as observed by me in 1858. It is impossible 
to compute the collective number of these lateral leaflets. It 
must be something enormous, as on some laminae I have 
counted more than fifty on each side. Taking only twenty- 
eight as the average, however, and estimating the number of 
laminae at 550, this will give us a total of 80,800 ! When 
speaking of the minute structure of the wall, we will again 
refer to this arrangement of the leaves. 
The upper border of the wall is the circular, attenuated, 
concavo-convex part, partially entering into the composition 
of the coronet. The concavity is situated on the inner sur- 
face, and is semi-cylindrical or ovoid ; it extends along the 
whole of the upper border as far as the centripetal prolonga- 
tion at the heels, where it disappears along with the laminae 
on their internal face. 
This large space, designated the u cutigeral cavity, 5 ’ is 
partly hollowed out at the expense of the wall, and affords 
lodgment to the coronary cushion and zone, whose convexity, 
width, and general contour it closely follows, being widest 
and deepest in front, and gradually decreases as it proceeds 
backwards, until it reaches the angles of inflection, where it 
suddenly becomes enlarged to receive the greatly increased 
superficies of the cushion, and then diminishes until it finally 
disappears with the last lamina of the bars. The anterior 
border of the cavity is higher than the inner or posterior 
border, and is also very thin and sharp, to coincide with its 
commencement at the coronary fissure already mentioned. 
This thin margin is covered by the “ periople ” or coronary 
frogband, to be noticed presently. The posterior or lower 
border of the cavity is marked by an even and faintly depressed 
space passing above the origin of the horny laminse, which 
corresponds to the coronary zone that forms an apparent line 
of separation between the coronary cushion and the vascular 
laminse. This imprint of the zone is consequently narrowest 
in front and widest towards the heels; and, like the zone 
itself, is usually white in dark-coloured hoofs, or streaked or 
speckled with black. Between these two borders the entire 
surface of this wide groove is pierced by innumerable minute 
perforations that incline obliquely downwards from above to 
below in the direction of the Avail. The number, width, and 
depth of these tiny pores, — for their small size and great number 
give the whole of this recess a porous appearance, — correspond 
to the papilla? which we have mentioned as studding the 
superficies of the coronary cushion (fig. xii, e ), and Avhich 
enter and fill them. As a consequence, these horny sheaths 
are Avidest and deepest tOAvards the loAver or innermost aspect 
