70 ART. 3. S. IKEDA I CONTRIBUTIONS 



eggs of the corresponding number in Groups I., and IV. But 

 when punctured, the point was found to be above the level of 

 the dorsal lip, and to the right of the anti-blastoporic meridian 

 (i.e. to the left when seen from the blastoporic meridian). 

 Then another puncture was made : This time, it was at the 

 level of the dorsal lip but slightly to the left of the anti- 

 blastoporic meridian (i.e. to the right, when seen from the 

 blastoporic meridian). From the first puncture, a small 

 quantity of the egg-contents exuded through the egg envelope ; 

 from the second, a small protuberance was produced as an 

 ex-ovate inside the envelope. 



April 23, 7:15 a.m.: — Blastopore circle already finished. Ventral lip 

 has overcome the first ex-ovate and passed 10° beyond it, 

 but not yet detached from the second ex-ovate which is found 

 close to this lip. Dorsal and lateral lips grown much further, 

 55° - 60° below the equator. 

 3:07 p.m. : — Blastopore reduced to a small circular spot ; second 

 ex-ovate close to the right lateral lip ; first ex-ovate about 

 double the same distance from the ventral lip. 



April 24, 5:15 p.m. : — Blastopore closed. Embryonic body formed 

 normally. First ex-ovate at the distal end of the embryonic 

 body ; second ex-ovate, on the right side of the right neural 

 fold ; distance between the two unaltered. Growth therefore 

 must be by the dorsal and lateral lips. 



As the blastopore was closed about 10° below the first ex- 

 ovate, and the embryo extended dorsad from this, nearly the whole 

 of the embryonic body must have been formed on the yolk hemi- 

 sphere, below the first dorsal blastopore lip. (Cf. Fig. 80). 



Egg No. 6. 



Punctured close below the dorsal blastopore lip in the 

 median line, (Cf. the eggs of the corresponding number in 

 Groups I., and IV.). Twenty-four hours later, the blastopore 

 circle completed and all going well. Eight hours later, a 

 large new tubercle-like ex-ovate was discovered close below 

 the ventral lip. This was probably due in some way to the 



