DR KNOX on the Philosophical Anatomy, 8fc. 



the eye. I have not remarked in any adult quadrupeds, whose eyes were pre- 

 pared by me for dissection, any vessel, or branch of a vessel, passing through the 

 centre of the vitreous humor ; the whole of the arteria centrcdis retina being ap- 

 parently distributed, in the first instance, to the inner membrane of the retina. In 

 birds, as I have observed, it is quite the reverse. 



It is in the eye of the cat that most of the facts may be best observed ; for, in the 

 eyes of oxen, sheep, &c. the vessels are very apt to give way, and the injected fluid 

 becomes effused into the canal of Petit and betwixt the membranes. The principal 

 vascular union betwixt the two sorts of ciliary processes is close to the edge of 

 the lens. 



