Dissection of Eye of the Ox. 263 



posteriorly. There exists, however, a distinct and separate 

 middle chamber, anterior to the circumference of the Lens 

 (= the posterior chamber of old anatomists), viz.y in the 

 angular interval existing at the circumference between the 

 ciliary processes, the Iris, and the suspensory ligament of the 

 Lens. 



Reflection of Sclerotic. Let four cuts be now made 

 with the scissors through the Sclerotic from the edge whence 

 the Cornea has been removed, towards the optic nerve being 

 careful to cut through the Sclerotic alone, and let the four 

 resulting flaps be pinned down upon a cork so as to support 

 the Eye in an upright position : a thin structure* will be found 

 to unite the fore part of the Sclerotic to the front of the un- 

 derlying dark tunic called the Choroid ; this must be broken 

 through with the handle of the scalpel, as also some connec- 

 tions further back towards the optic nerve. 



The Choroid coat. Ciliary {cilium, an eyelash) processes, and 

 Iris are supplied by vessels from the Ophthalmic (6(j)daXfxoQ, an 

 eye) artery , named the anterior and posterior Ciliary vessels : of 

 these the posterior (short) ciliary branches pierce the Sclerotic 

 coat around and close to the Optic nerve : the anterior (long) 

 branches, arising in front of the orbit chiefly from muscular 

 branches, pierce the Sclerotic just behind the Cornea. The 

 Ciliary veins also perforate the Sclerotic at different points to 

 go to join the Ophthalmic veins. 



The inner aspect of the Sclerotic coat will be seen to be of 

 a dark colour, resulting from the presence of a delicate con- 

 nective tissue (Membrana Fused) through which branches of 

 the ciliary vessels pass obliquely : and which is thickest at the 

 back part of the eyeball, becoming thinner and whiter towards 

 the Cornea. On the inner surface of the Sclerotic, at its corneal 

 margin may be seen a circular groove passing round ; which 



* Vide infra, Ciliary muscle. 



