386 



ELECTRO-PHYSIOLOGY 



CHAP. 



Exact comparative observation of the different stages in the 

 development of the organ in Raja clavata in the same embryo, 



d 



f 



7 IT cm. in length (Fig. 254, a-c), leaves no doubt that both the 

 small, dark, and the broad, clear, transverse stria? of the original 



