FORMATION OF NEURAL CANAL. 



31 



cum. 



3H. 



IV. 



Fig. 32. SECTIONS SHOWING STAGES IN THE CONVERSION OP THE MEDULLARY GROOVE INTO THE 



NKURAL CANAL. FROM THE TAIL END OF AN EMBRYO OP THK CAT. (K. A. S.) 



cp, me, hy, epiblast, mesoblast, and hypoblast ; m.g., medullary groove ; n.c. (in IV.), neural 

 canal ; ch, notochord ; cos, ccelom ; am, tail fold of the amnion. 



