264 
RUPTURE OF THE COLON IN A HORSE. 
bones (in the human subject the frontal does not contribute 
to its formation); the inner part is formed by the sphenoid, 
etiimoid, palatine, and superior maxilla (the cavity of the 
orbit in the human subject has no post. orb. iossa); it is clothed 
with a shell of bone. 
The eyeball is placed nearer to the frontal than to the tem¬ 
poral side; the globe is suspended in front of the eyelids, 
laterally and posteriorly, by its muscles and by the optic 
nerve, which, together with its vessels, are enveloped in fat; 
the size of the globe differs in different individuals; some 
large horses have small eyes; again, small horses are seen 
with large eyes, and so on. Its figure is said to be a com¬ 
pound of two spheres of different diameters, united in front 
by an elliptical line. Its axis points to a horizontal line more 
outward than forward, and more forward than downward ; this 
line intersects another horizontal line drawn directly outward 
at an angle of about 70°, and one drawn directly outward at 
about 20°; the inclination downward, however, will vary with 
the position of the head. The axis of the eyeball is not exactly 
that of the orbit, though it likewise takes a direction more 
outward than forward, for in the ordinary position of the 
head it is perfectly horizontal, and in consequence of the 
prominence of the eye next the temple, inclines more forward 
than the orbital axis, probably by 10°; the motions of the eye 
will vary its axis considerably, and especially in the lateral 
direction. The eyes, placed as they are in the head, command 
nearly a whole sphere of vision ; thus the horse is amply pro¬ 
vided with visual means for seeking food and avoiding danger. 
To my notes, taken at Professor Spooner’s lectures when a 
student, to Wilson’s ‘Vade Mecum’ and Percival’s ‘Anatomy’, 
I am indebted for the refreshing my memory has received in 
enabling me to be so precise in the anatomical description of 
the eye and its appendages. 
{To he continued^ 
COMMENTS ON A RECENT CASE OF RUPTURE 
OF THE COLON IN A HORSE. 
By J. C. Broad, M.R.C.V.S., Market Street, Paddington. 
In the Yeterinanan for last month a case of rupture of 
the colon of a horse is reported by Mr. Billington, of 
Henham, Essex, who expresses an opinion that the rup- 
