HEPWORTH, ON THE STRUCTURE OF THE HORSE’S Foot. 247 
supposed & priori would have torn the coffin-bone (os pedis) 
from the wall of the hoof. If you fancy two volumes, with 
leaves of vellum, slightly moistened and locked together leaf 
by leaf, contaiming one thousand to twelve hundred pages, it 
will give a good idea of the arrangement of the two sets of 
laminze, and the difficulty of separating them. I have a spe- 
cimen of hoof in which I have counted five hundred and ten 
laminee, including the bars. Mr. Percivall has met with six 
hundred. The sensible and insensible lamin are not only 
united singly, but doubly. Mr. G. Fleming (Veterinary 
Surgeon to the 83rd Hussars) has discovered lateral pro- 
cesses on the laminz similar to the featherlets of a quill 
(Pl. X, fig. 1, ¢), which he has called laminelle ; they appear 
to be given off from the lamine in single fibres; by examin- 
ing a thinly cut section with polarized light, they will be very 
clearly seen. 
The wall of the hoof is hollowed at the upper and imner 
side, leaving the front edge thin, and forming an ovoid cavity, 
the posterior edge being much lower than the anterior. The 
coronary substance is adapted to, and imbedded in, this 
groove, which is perforated by innumerable orifices, through 
which the villi (fig. 2) pass down into the wall parallel 
with its front surface. They are about 5%; inch long, and 
covered with numerous blood-vessels. These villi secrete the 
wall, and, I believe, the lamine also. Ifa transverse section 
(Pl. XI, fig. 1) be carefully examined, it will be found that 
round each orifice there are annular rings, with dark-coloured 
cells; the structure is not unlike bone, but the cells have no 
canalicule. I believe them to be pigment-cells, although 
more distinct with a high power than those in whalebone, 
with which I have compared them. These cells extend into the 
laminz, and there are vestiges of them to the very extremities, 
to be seen with a good quarter-inch objective. The horn- 
cells also evidently come out from the wall, giving the la- 
mine a fibrous appearance. There is no line of demarcation 
between the substance of the lamine and that of the wall, 
which would be the case if they were secreted by another set 
of vessels. I drew some injected villi from the wall, to which 
were attached many of the pigment-cells, and which adhered 
so firmly to the basement membrane, that I could not remove 
them by washing and brushing rather roughly. I have not 
been able to detect the least appearance of any such cells, 
either on the sensible lamine or their vessels. I met with 
an instance where these laminz gave off several villi* about 
* Messrs. Lawson and Fleming consider this an unusual distribution of 
the villi. 
