606 OK THE MECHAKISM OF THE EYE. 



Fig. 102. Part of the choroid of the cod fish, with its red substance. The central aiterj 

 hangs loose from the insertion of the nerve. 



Fig. 103. The membrane covering this substance internally, raised by the blowpipe. 

 Fig. 104. Th« appeaianceofthe Ted substance, after the removal of the membrane. 



