UHjlArf ■_,■« 



Ch.P 

 L.V. 



I.P.R. 



&■ 



~ ^ 



O 



'' Yy-»" 





«kS.~" : ' ": ■-.V'v-"-'"'"/' .1? ; -'V*V<f/-! -.''" 



■S.D. 



PS. 



■P.Co. 



Fig. 196. — Upper : Medial longitudinal section of a chick embryo (8 days), showing 

 the main pineal diverticulum and secondary diverticula, which have arisen as 

 hollow outgrowths of the former ; also the relation of the superior and 

 posterior commissures to the stalk of the main diverticulum, and the dorsal sac. 

 Lozver : Oblique coronal section of pineal organ of a chick embryo, of the same 

 age as A, showing the primary and secondary diverticula and some fibres of 

 the posterior commissure. 

 Ch.P. V .III. : choroid plexus of third P. Co. : posterior commissure. 



ventricle. P.S. : pineal sac. 



Ch.P. LV. : choroid plexus of lateral 5. C. : superior commissure. 



ventricle. D.S. : dorsal sac. S.D. : secondary diverticula. 



I.P.R. : infrapineal recess. 



19 



