194 
MR. YOU ATT S VETERINARY LECTURES. 
separated it from the orbit of the eye. To give free play to the 
bone, and to afford a cushion on which the posterior part of the 
eye, or this membrane, might rest, a great deal of cellular mem¬ 
brane and fat was placed in this cavity. While the animal was 
young, and so long as the secretions were abundant, this cavity was 
well tilled ; but when, as old age came on, the absorbent ves¬ 
sels were more active than the nutritive ones, the fat was gradu¬ 
ally removed, and the falling in of the skin of the forehead in¬ 
dicated the loss of substance underneath, and the progress of 
age. It is said that some of the lower class of horse-dealers 
puncture the skin, and blow into the orifice with a tobacco-pipe, 
or small tube, until this depression is almost filled up. In 
slang language, this is puffing the glims , and, with the aid of a 
bishopped tooth, may give a false appearance of youth that may 
deceive the unwary. 
The suture between the frontal and temporal was described as 
exceedingly strong, to prevent the walls of this important arch 
from bulging out. 
The Lecturer then shewed the wing of the aethmoid bone, re¬ 
ceived into a kind of notch between two portions of the frontal, and, 
immediately below this notch, and on the suture, the foramen 
orbitale internum for the passage of the lateral nasal branch of 
the fifth pair of nerves. He next traced its connexion with a 
small portion of the wing of the sphenoid bone, it now taking a 
direction anteriorly, and, pursuing the same direction, skirting 
the orbital process of the palatine bone, sending a small process 
between the lachrymal bone and the superior maxillary, and then 
taking a direction anteriorly, until it arrived at the side of the exca¬ 
vation for the lachrymal sac, then suddenly turning upward and 
emerging from the orbit at the inner canthus or angle of the eye. 
He now traced the bone upward, as forming the upper part of 
the inner wall, and the whole of the roof of the orbital cavity. 
This is called (he said) the external orbital process, and reaches 
to the zygomatic arch. It is convex outwardly, and concave 
inwardly. Its concavity receives, superiorly, and nearly over the 
outer angle of the eye, the lachrymal gland. Towards and over 
the inner angle is a remarkable depression, for the reception of 
the pulley of the Trochlearis or superior oblique muscle. The 
arched form of this process gives it the strength that is required 
to protect the eye; and especially requisite, as the roof of the 
orbit is a part exposed to considerable danger from accident or 
brutal violence. Mr. Pritchard, of Wolverhampton, had a case of 
fracture of the orbit, which he treated with so much judgment, 
and such complete success, that I will relate it to you. A mare 
had a blow over the eye, which fractured the orbit, from the su¬ 
perciliary foramen to the outer angle of the eye. The detached 
