TO THE EMBRYOLOGY OF AMPHIBIA. i\) 



5:55 p.m.: — Blastopore area and area of the segmentation cavity 

 much diminished in size in equal ratio. Dorsal lip, however, 

 not grown any further, so that the reduction of the blastopore 

 area at this stage is due to the growth of the ventral and 

 lateral lips. Secondary ex-ovate beneath the dorsal lip still 

 more increased in size. 



April 30, 9:23 a.m. : — Blastopore area diminishing faster than the 

 area of the segmentation cavity, though both are now much 

 reduced. Two ex-ovates still at their antipodal positions. 

 5:25 p.m.: — Area of the segmentation cavity disappeared. Bla^to- 

 p iv closed. Rndiment of medullary groove (primitive groove?) 

 seen in front of the lower ex-övate; Other embryonic parts 

 not made out. 



May 1. 7:14 a.m.: — No further progress. 



The final point of the blastopore closure in this egg was no 

 doubt about the lower punctured point (yolk-pole), and the loca- 

 tion of the imperfect embryo was as usual between the two poles. 



Egg No. 9. 



Punctured at the approximate upper pole (see Group IV., 

 Egg No. i» ; Grronp II., Egg No. 3). Puncture light. Develop- 

 ment proceeded normally and the embryo formed normal. 

 At the end the ex-ovate found about 20° forward from the 

 embryonic head-end, and about 25° to the right of the pro- 

 duced embryonic axis. 



Egg No. 10. 



April 28, 1:30 p.m.: — Punctured at a point approximately midway 

 between the yolk-pole and the auti-blastoporic point, as in the 

 eggs of the corresponding number in other groups. Piercing 

 rather forcible, but not as much as in Group II., Egg No. JO. 

 Soon afterwards a second small ex-ovate was produced un- 

 expectedly close under the dorsal lip. 

 5:10 p.m. : — Dorsal lip grown somewhat downwards and increased 

 in length, has changed its position very peculiarly to the left 

 side of the egg between the first and second ex-ovate. 



