NEURAL TUBE 



OLFACTORY PLACODE H,,-^. 









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OLFACTORY PLACODE 



Fig. 1 Transverse section of an embryo 112 hours from fertilization with the 

 olfactory placode in contact with the neural tube. X 400. 



Fig. 2 Embryo of 120 hours cut transversely showing two small rami of the 

 olfactory nerve. X 400. 



115 



