404 MR. youatt’s veterinary lectures. 
These muscles deserve a fuller demonstration than I have time 
to give them ; and you will ere long have the opportunity of at¬ 
tending on that demonstration. I have been compelled to men¬ 
tion them, in order that you may better understand the connexion 
and function of these important parts. 
The Os Hyoides of the Ox *—You will at once perceive a con¬ 
siderable dissimilarity of structure between this bone in the horse 
and the ox. The spur is almost vanished—-nothing remains but 
a little tubercle, to which, indeed, the same muscles are attached, 
but not with equal power. The shorter cornu on each side is mul¬ 
tiplied into two, and the larger cornu terminates in a bifurcation 
of bone ; and one of these bifurcations is not merely united to the 
temporal by cartilaginous adhesion, but a curious socket is formed 
between the mastoid process of the temporal bone, and a plate of 
bone let down for the purpose, in which the extremity of the cornu, 
swelled out into a head or tubercle, is received, and plays loosely 
yet securely. It is evident, then, that the tongue, freed from its 
attachment to a bone that runs deep into its root, has a more ex¬ 
tensive action, and that this freedom of action is increased by the 
additional joints formed by the second shorter cornu. 
I am not aware of any animal whose tongue requires so little 
extent and freedom of motion as the horse. He is not designed to 
graze closely, and his tongue is seldom or never employed in 
gathering his food. He is also doomed to be guided, and 
often cruelly restrained, by the bit. A tongue of considerable or 
of loose motion would be an inconvenience to him : under the 
unequal pressure of the bit, it would roll from one side to the 
other, and be excoriated or lacerated by the teeth. Thus tied down 
by the spur or appendix of the hyoid bone, it forms a useful pad 
on which the bit may rest, and on which it may work. The jaw 
which, even now, is too often injured by the bit, would be 
exposed to yet more frequent and severer injury. Therefore the 
tongue of the horse is thus confined. I know but one animal, the 
hare, in the hyoid bone of which this spur is found. 
The ox has need of a far more flexible tongue. He bites much 
more closely to the ground, and, being destitute of teeth in 
the upper jaw, their place being supplied by a mere pad, he needs 
the aid of his tongue to curl round the grass to bring it into the 
mouth, and to help to hold it there until it is partly bitten and 
partly torn asunder. If you will observe a horse and a cow while 
grazing, you do not see, or scarcely see, the tongue of theone, while 
the tongue of the other is protruded at every bite, and is wrapped 
round the grass in the manner to which I have just alluded. 
Grazing thus closely to the ground, the ox is subject to an an¬ 
noyance from which the horse is in a manner free. He is conti- 
