MEDIAN AND VERTICAL SECTION DF A TWO AND 

 DNE-HALF MONTHS' EMBRYO, [His.] 



[Considerably Enlarged.] 



1, Aqueduct of Sylvius. 2, Medulla Dblongata. 3, Cerebellum. 

 4, Pans Varolii. 5, Anterior Tubercula QuadrigEinina. B, Posterior 

 Tubercula Quadrigemina. 7, Infundibulum and Pituitary B o dies. 

 B, Tuber CiriEreum. 9, Dptic Thalamus. ID, Fourth Ventricle. 

 11, Hypoglossal Nerve [Twelfth Pair], 12, Third Ventricle. 13, 

 Hemisphere Vesicle, 



