92 



THE EYE 



3. The Retina. 



Mount in balsam one of the prepared sections of the posterior 

 part of the frog 1 8 eye: examine with low and high powers. 



PC 



FIG. 18. 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; Q, ganglion cell; ll_, inner 

 limiting membrane; IM, inner molecular layer; IN, 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. 



