



Fig, 14. — Retina pig 



A, ganglion cells 



B, pale cells. 



mMit ^ 



mMM^M 



'S 8 





Fig. 15. — Retina pig ; 

 A, ganglion cells ; B, 

 reticular layer ; C, 

 layer of pale cells. 



*^^ 



<irss^ 





Fig. 16. — Pig, 2}4 cm. 

 long ; A and B. 

 frontal sections 

 through inferior wall 

 just after closure of 

 cleft; C, D, E, optic 

 stalk. 



V 



f- %.^: 



^r 





Fig. 17. — Pig, 4^^ cm. long ; sagittal section 

 optic nerve ; A, collection of epiblastic cells 

 among nerve-fibres ; B, entrance of central 

 vessels. 



Fig. iS. — Pig, Optic 

 nerve ; A, nerve fi- 

 bres ; C, sheath. 



