STAGING OF AMPHIBIAN EMBRYOS 



67 



THE NORMAL STAGES IN THE DEVELOPMENT OF THE 

 SOUTH AFRICAN CLAWED TOAD, XENOPUS LAEVIS 



STAGE NUMBER 



AGE-HOURS, IB'C 



n 



UHTEimuZEO 



® 



tMILV CLItVAOE 



STAGE NUMBER 



AGE-HOURS, 18-C 



MIO - QASTttUL' 



NEUOAI. pl.aTE 



STAGE NUMBER 



AGE-HOURS. le'C 



Muiiu. Tuac 



STAGE NUMBER 



AGE IN HOURS AT I8*C 



39 



43 



LENGTH IN MILLIMETERS 



55 



MUSCWLAM REirOMSC 



■ tU. BtIB ST«a( 



STAGE NUMBER 



IGE IN HOURS AT I8'C 



LENGTH IN MILLIMETERS 



SECOND- rORM TADPOLE 



THIRD - f OttM TADPOLE 



Drawings: Courtesy 

 Dr. Paul Weis2 1945: 

 Anat. Rec. 93 



Dorsal, lateral and ventral views of a 

 35 mm. larva of Xenopus loevis. 



Photo: Courtesy 

 Dr. Paul Weisz 1945: 

 Jour. Morph. 77 



