72 AKT. 3. — S. TKEDA : CONTRIBUTIONS 



2:50 p.m. : — Blastopore greatly reduced in size, but a very large 

 mass of the esg-con tents had been exuded from the ventral 



CO 



margin of the small blastopore, concealing from view that 

 region. First ex-ovate still attached to the right lateral lip. 

 Neural groove faintly recognized in front of the dorsal lip. 

 April 25, 5:25 p.m. : — Large secondary ex-ovate larger in size by addi- 

 tional exudation covering the posterior part of the egg but 

 apparently entirely detached from the exuding part. Blasto- 

 pore barely closed in front of the large ex-ovate. Original 

 ex-ovate attached to the right margin of the tail fold, showing 

 that the blastopore must have closed near the region when 

 the dorsal lip first appeared. Embryo very imperfect : head 

 could not be detected in the external view ; tail well formed. 



Although the formation of the embryonic body in this egg 



was very incomplete, the results in regard to the final point of the 



blastopore closure and the location of the embryonic body agree 



in the main with those obtained from Group IV., Nos. 2, 6, and 



7 ; Group L, Nos. 6 and 8, and No. 6 of this group. 



Egg No. 9. (Figs. 91 a-d, Fig. 92). 



April 23, 9:00 + a.m. : — (Fig. a). Puncturing was intended to be at 



the exact yolk-pole, but was in fact slightly to the right in 



the posterior view. 

 April 24, 7:55 a.m.:— (Fig. b). Blastopore area greatly reduced, 



circular in shape but connected with the ex-ovate by an arm 



on the right lip. 

 2:45 p.m. : — (Fig. c). Blastopore now reduced to a very small 



circle. Ex-ovate now outside of it to the right. Neural 



plate faintly visible. 

 April 25, 5:30 p.m. : — (Fig. d). Blastopore completely closed. General 



outline of the embryonic hcdy well made out : ex-ovate is at 



the exact axial end of the embryo, and the final closing point 



of the blastopore a little to the left of it did not become 



the tail end. 



The diagram of this egg is given in Fig. 92. Although there 



