STAGING OF AMPHIBIAN EMBRYOS 



61 



VEGETAL POLE 



UNFERTILIZED EGG - STAGE 



«RtA OF VtWCLE 



FERTILIZATION - STAGE 2 



POLAR BOD 



■iP^ ™^ %P 



FIRST CLEAVAGE - STAGE 3 

 (POLAR VIEW) 



(RANA PIPIENS) 



