HOMOLOG1CAL STRUCTURES. 



11 



Pig. 1. Upper figure human embryo, 



- Lower figure that f a d g ' 



a. Pore-brain, cerebral hemispheres, 

 etc. 



b. Mid-brain, corpora quadrigemma. 



c. Hind-brain, cerebellum, medulla 

 oblongata, 



d. Eye. 



/. First visceral arch. 

 a Second visceral arch. 

 H. Vertebral columns and muscles 

 in process of development. 



L. Tail or os coccyx. 



