230 



HUBERT DANA (K)ODALE 



marks were close together. Apparently the egg was about read 3 

 for the formation of the neural folds. 



Series B. No. 2 (figs. 69-73); marked at 7:40 a.m. (fig. 69). 

 A semi-circular blastopore was present. A stained spot lay above 

 the blastopore a little to the left of the middle. Below the left 

 corner was another, faintly stained. At the next observation, 

 11:40 a.m., (fig. 70), the blastopore appeared less extensive than 

 before. The mark above the blastopore now extended into it, 



64 



66 



67 



68 



Figs. 64-68 



apparently having elongated in part and in part moved bodily 

 towards it. The lower mark was not as close to its corner as 

 before. 3:05 p.m., (fig. 71) conditions were much the same as at 

 11:40. 6:45 p.m., (fig. 72), the blastopore had moved clockwise 

 in reference to the marks so that the upper mark now lay at the 

 left corner while the lower lay a little below the right corner. 

 Next morning (fig. 73) the blastopore had shortened, leaving 

 both marks some distance ventral to it. 



Series B. No. 1, drawn at 8:00 a.m. (fig. 74). Especial at- 

 tention is directed to the A and B marks, the latter a small one 

 which lay close to the blastopore, while the former lay above 

 and a little to the right. 11:40 a.m. (fig. 75) only one-half of 



