30 AKT. 3. — S. IKEDA : CONTRIBUTIONS 



cleavage line. In the same way, in the left and right side views 

 of the egg, when the dorsal lip came to he in the profile, the 

 rotating dish stood at 175° (Fig. 45) and 355° respectively. This 

 showed that the meridian of the blastopore coincided with the 

 plane of the second cleavage and stood at 90° to the plane of 

 the first cleavage. 



The blastopore did not close in a circle during this day, but 

 when seen next morning, (the 4th day), the encircling had been 

 completed and the blastopore rim had grown downward all 

 around to about 70° below the equator. Fig. 46 represents the 

 left side view at 8:20 a.m., and corresponds to Figs. 26 and 27 

 of the Rhacophorus egg, and to Fig. 40 of the liana egg. As 

 in all these figures, the dorsal, ventral, and lateral lips of the 

 blastopore are all at the same level and the egg rests on the 

 approximate middle point of the blastoporic area. 



At 1:30 p.m., on the same day, the egg (Fig. 47) had 

 rotated about 32° or 33° and the blastopore had diminished to 

 about j 3 in its diameter as compared with that in Fig. 46. One 

 hour later at 2:30 p.m., the dorsal lip had returned to its first 

 starting point and the ventral lip was about 20° dorsad of the 

 resting point of the egg, for in addition to the egg rotation the 

 blastopore was now still more diminished in diameter. Toward 

 the evening of that day, the closure of the blastopore was far 

 advanced but the general outline of the embryonic body could 

 not yet be recognized (Fig. 48). On the morning of the fifth 

 day, the blastopore was nearly closed, leaving only a small yolk- 

 plug exposed, and the first trace of the neural groove and folds 

 could be detected in front of the small blastopore. Fig. 49 gives 

 the posterior view of the egg at 8:30 on that morning (the fifth 

 day). Although the embryonic body is not sketched in, it will 



