ON THE SENSE OF TOUCH IN THE HORSE’S FOOT. 647 
velvet out of its surface, denominated its papilla or villo-papillce. 
These villous papillae are received into horny sheaths, which con- 
duct them through the substance of the hoof, as it were, for the pur- 
pose of meeting sensations, and in such manner, by their number, 
their bulk, their protraction, their volume, and, above all, by their 
exquisite sensibility, compensating for their unfavourable situation 
beneath the horny breast-plate covering them, which would neces- 
sarily have rendered their sensorial faculty obtuse had it not been 
for these circumstances. 
The faculty of touch is not that assigned by authors in general 
to the foot of the horse. They consider the papillae as the essen- 
tial organs of secretion ; whereas we, having analogy to support us, 
endow them with the power of feeling. 
Are not the papillae of the horse’s foot similar to the papillae at 
the extremities of the fingers of man, whose functions as organs of 
touch are indisputable 1 And again, are the horse’s feet not ana- 
logous in their papillary developments to the paws of the cat, 
the claws of birds, and in particular to such as, like the parrot and 
birds of prey, make use of their claws as instruments of prehension 
and touch. 
Why should the papillary structure exist in the horse’s foot? 
Is it of a different use there from what the same structure serves 
in other animals ! And were not such analogical inferences fairly 
deducible, we might argue from the very situation of the papillary 
prolongations of the foot what their use was. Whereabouts do we 
find them ! 
First of all, upon the frog, at the summit of its parietal fibres, 
opposite to the extremities of those (sensitive) fibres which are 
directed towards the ground, thereby coming immediately under the 
influence of sensations transmitted from the ground through conti- 
nuity of the parietal fibre. Should the thickness of horn and the 
distance this places the papillae at from the objects by which they 
become impressed be raised as objections to such functions, it may 
be answered, that such a disposition of parts is common to animal 
organization, and that natural history furnishes many examples 
shewing that the nervous pulp preserves an exquisite sensibility in 
spite of any external covering it may have. The teeth are sensi- 
ble to a very light touch notwithstanding the thick layer of ivory 
separating the interior pulp from the body impressing them. 
Again, in many animals, the most delicate instruments of touch 
are the long hairs issuing from their lips, though they are nothing 
more than inert flexible shafts interposed between external bodies 
and the sensitive pulps into which they are implanted. And, to 
take an example bearing some analogy to the subject in question, 
the beak of the duck possesses extremely minute tactile cognizance, 
