506 COMPARATIVE ANATOMY AND PATHOLOGY. 
so serious, and in which the fracture does not extend beyond the 
anterior edge of the arch. I am speaking now of the horse. 
M. Leblanc has had great practice, with regard to these acci- 
dents, among the horses drawing the hired vehicles of Paris. An 
abbreviation of his excellent remarks will not be unacceptable to 
you. 
He has never had a case of complete fracture of the orbital arch, 
but he has seen many in which the injury has been confined to its 
edges, or a very little way beyond. If a complete cure has not 
been effected, from neglect of perfect reduction of the fracture, at 
least complete loss of sight has never occurred : he should regard 
a case of complete fracture as exceedingly dangerous, especially 
if any of the nervous branches which are here distributed should 
be injured; nor does he think that the bulb of the eye could escape 
unharmed after a concussion sufficiently great to produce frac- 
ture of the arch. 
Partial fractures of the arch are the more frequent, because the 
bone is there covered by little more than the simple integument. 
Although he has never seen actual loss of sight produced by this 
accident, he can readily imagine that it may occur when there was 
some inflammation or predisposition to inflammation in the organ. 
I can believe that it may favour the development of habitual 
fluxion from the eye, and, generally speaking, aggravate every dis- 
ease, or tendency to disease, that may have previously existed. 
The existence of this kind of fracture is readily determined, by 
introducing the thumb under and pressing the fore-finger upon the 
edge of the orbit, where the blow seems to have fallen, or any 
deformity appears. 
The mode of treatment recommended differs very little from 
that adopted by Mr. Pritchard — the replacement of the fractured 
parts, the application of the suture, frequent fomentations, low 
diet, and aperient medicine. 
I have seen several cases of sad contusion on the forehead of 
the ox, but not one of fracture ; and yet I have often been told, 
and I have so written, that fracture of the superciliary arch is more 
frequent in the ox than in the horse. I have already said, that as 
this is a part particularly exposed to danger, nature has be- 
stowed on it sufficient strength to bid defiance to accidents of this 
kind ; but I shall have to speak of other evils resulting from violent 
blows on the orbital arch of the ox. 
We should scarcely expect often, or at all, to meet with cases of 
fracture of the orbital arch in the dog, because in that animal 
cartilage, or a cartilago-ligamentous substance, occupies a very con- 
siderable portion of that arcade ; but I have again and again, amidst 
