HISTOLOGY. 125 



The lens is a biconvex body, placed between the an- 

 terior and posterior chambers of the eye, and held in 

 place by the suspensory ligaments. The anterior cham- 

 ber is filled with a clear fluid called aqueous humor, 

 and the posterior, with a fluid called vitrous humor. 

 The lymphatics are found around the nerves of the 

 eye and in a few other places. The nerves are derived 

 from the ciliary nerves. The retina contains ten layers. 



1. The layer called internal limiting membrane. 



2. The layer of nerve fibers. 



3. The layer of ganglion cells. 



4. The inner molecular layer. 



5. The nuclear layer. 



6. The outer molecular layer. 



7. The outer nuclear layer. 



8. The external limiting membrane. 



9. The layer of rods and cones. 

 10. The layer of pigment cells. 



Make sections of tissue supplied, according to direc- 

 tions. 



THE EAR. 



The special organ of the sense of hearing is lo- 

 cated in the ear. The ear is of rnesodermic origin. 



