PLATE 3 



EXPLANATION OF FIGURES 



(Cryptobranchus allegheniensis) 



All the figures are from preserved material, fixed in bichromate-acetic-formalin 

 excepting the eggs shown in figures 210 and 212 which were fixed in formalin. The 

 animal hemisphere is shown in every case. X 4. 

 204 Stage 1. First cleavage. 



Second cleavage. 



Third cleavage. 



Fourth cleavage. 



Fourth cleavage. Figure 82 is drawn from the same egg. 



Fourth cleavage. Figure 81 is drawn from the same egg. • 



Thirteen micromeres. Figure 87 is drawn from the same egg. 



Seventeen micromeres. Figure 86 is drawn from the same egg. 



About thirty-two micromeres. Figure 98 is drawn from the 



About thirty-two micromeres. 

 About thirty-six micromeres. 

 About sixtv-four micromeres. 



564 



