54 ART. 3. S. IKEDA : CONTRIBUTIONS 



the accessory dorsal lip. Ex-ovate attached to the closing 

 point of the actual blastopore. Embryo short, although other- 

 wise not greatly abnormal, its axis turned about 14°-15° to 

 the right. 



It seems to me that in this egg, the hlastoporic area has 



somehow become divided into two entirely separate parts : (1) the 



upper smaller part which was represented by the accessory lip 



and which completed itself in a circle separate and smaller ; 



and (2) the lower, larger, main part which closed itself finally 



at the point of puncture, the overgrowth of the yolk having been 



effected mostly by the ventral and lateral lips. Moreover the 



embryonic body must all have been formed in front of the injured 



spot, i.e. mostly in the original upper hemisphere of the egg. 



Fig. 77 gives the diagram of this egg. 



Egg No. 3. (Figs. G9 «-/, Fig. 78). 



May 5, 12:40 p.m. : — (Fig. a). Punctured at the periphery of the 

 translucent area of the segmentation cavity, in front of, and 

 in the line of the first appearing dorsal blastopore lip. 

 4:40 p.m. : — (Fig. b). Dorsal blastopore lip has grown somewhat 

 downward and in length, and shows a more than usually 

 crescentic curve at the highest point of which the ex-ovate 

 is now attached. 



May 6, 8:12 a.m. : — (Fig. c — posterior, Fig. e?=left side view). Very 

 peculiar aspect. Blastopore circle finished, but unusual in 

 appearance. Ventral part round and smooth, but a gradually 

 narrowing arm sent dorsad, and the ex-ovate attached at the 

 tip. Segmentation cavity likewise peculiar, and elongated 

 antero-posteriorly. 

 4:19 p.m. : — (Fig. e). Area of the segmentation cavity entirely 

 vanished. Blastopore grown much smaller and almost circular, 

 but still connected by a narrow slit with the ex-ovate. General 

 outline of the embryonic shield faintly recognized. 



May 7, 9:10 a.m. : — (Fig. /). Medullary groove and folds well re- 



