92 



THE EYE 



,3. The Retina. 



Mount in balsam one of the prepared sections of tlie posterior 

 yofrt of the frog' 8 eye : examiine with low and high powers. 



Fig. i8. — Vertical section through the posterior wall of the eye of a 

 frog ; the section passes through the sclerotic, the choroid, and the 

 entire thickness of the retina, x 300. 



BC, red blood corpuscle ; C, cone ; G, ganglion cell ; IL, inner 

 limiting membrane; IM, inner molecular layer; BN, inner nuclear 

 layer ; NF, layer of nerve fibres ; OL, outer limiting membrane ; 

 OM, outer molecular layer ; ON, outer nuclear layer ; P, pigment 

 cell of retina ; PC, pigment of choroid ; R, rod ; RF, radial or Miiller's 

 fibre ; 8, the cartilaginous sclerotic. 



