364 Journal of Comparative Neurology. 



a. — aqueous chamber //. — lower eye lid 



ax. — axones msc. — eye muscles 



iv. — blood vessels «. — nucleus 



c. — cones «/". — nerve fibers 

 <hr. p. — choroid and pigment layers nl. — nucleolus 



tl. — eye cleft n. op. — optic nerve. 



en. — cone nuclei nr. — nucleus of rods 



c. op. — cells of optic nerve 0771. — outer molecular layer 



(or. — cornea on. — outer nuclear layer 



d. — dendrites r. — rods 



e. — eye r. c. — rod and cone layer 



gc. — ganglion cells s. — space caused by separation of re- 



»'. — iris tina from pigment layer 



im. — inner molecular layer scl. — sclerotic 



in. — inner nuclear layer sh. — sheath of optic nerve 



I. — lens sk. — skull 



Ic. — lens cells ul. — upper eyelid. 



/. cp. — lens capsule v. — vacuoles 

 vc. — vitreous chamber. 



PLATE I. 



Fig. I. Lateral view of an adult head after the fur was removed to show 

 the position of the eyes and the very much reduced external ear. X i- 



Fig. 2. Lateral view of adult skull showing relative position of eye and 

 socket. X !• 



Fig. J. Dorsal view of adult skull showing relative position of the eyes. 

 X I. 



Fig. 4. Vertical section through the head of a young mole at birth. The 

 section passed through the center of the eye cleft and lens. X I3- 



Fig. J. Horizontal section of the head of a young mole at birth passing 

 through the eye tangentially and almost parallel to the eye muscles {77isc). In 

 the different sections the optic nerve can be traced along these muscles to the 

 skull. The arrow points anteriorly. X I3- 



Fig. 6. Horizontal section of the same head as Fig. i. Section passed 

 through the center of the lens (/). The different layers of the retina, portions 

 of the eye muscles (msc) and the optic nerve («. op.) are easily discernable. 

 The arrow points anteriorly. X 29. 



Fig. 7. Horizontal section of same head as Fig. 5 passing through the 

 optic nerve («. op.). A short distance from the eye the nerve shows the pecu- 

 liar granular appearance which is characteristic at this stage. The arrow 

 points anteriorly. X 29. 



Fig. 8. Horizontal section of same head as Fig. 5 passing through the 

 eye cleft. The arrow points anteriorly. X 29. 



PLATE n. 



Fig. g. Horizontal section of right eye of adult hardened in Perenyi's 

 fluid. Section passes through the center of the lens and the exit of the optic 



