126 



ANATOMY OF THE DOMESTIC FOWL 



Fig. 26.— Structures of the eye and nasal passage. 



A. I, The anterior turbinated bone. 2, The posterior turbinated bones. 3, 

 Orbital gland. 4, Ophthalmic division o£ the fifth pair of cranial nerves. 5, 

 Section through the cerebrum. 6, Section through the skull showing the air 

 spaces. 7, Section through the comb. 8, Anterior portion of the upper beak. 

 9, Edge of the hard palate. 



B. The intrinsic muscles of the eyeball, i, Superior rectus. ^, Internal 

 rectus. 3, Inferior rectus. 4, External rectus. 5, Superior oblique. 6, In- 

 ferior oblique. 7, Quadratus. 8, Pyramidalis. 9, Optic nerve. 10, Edge of 

 membrana nifctitans. 



C. Posterior part of the eye showing at the inferior portion of the ball the 

 pyramidalis muscle at i, and at 2, the quadratus. 3, Optic nerve. 



D. Inner view of the posterior part of the vitreous chamber, i, Sclerotic 

 coat. 2, Choroid coat. 3, Retina. 4, Pecten. 



E. Longitudinal section through the eye of a hen. i, Cornea, ii, Anterior 

 chamber. 3, Scleral ring. 4, Crystalline lense. 5, Iris. 6, Retina. 7, Scler- 

 otic. 8, Choroid. 9, Pecten. 10, Optic nerve. 11, Vitreous chamber. 



F. An edge view of the crystalline lense of a hen showing it to be asymmetrical 

 biconvex, i. The anterior side. 2, The posterior side. 



G. The upper section through the anterior portion of the anterior turbinated 

 bone showing one complete circle and the lower a section through the middle 

 turbinated showing one and one-half turns. 



