84 



MARY GRACE SPRINGER. 



elusive results. No results were obtained, however, which were 

 in any way contradictory to those previously noted. 



Series 56. 



An experiment was made, using motile blastulse for extract, 

 but instead of sea water, distilled water was employed, and the 

 crushed eggs left over night (12 hours) in the distilled water 

 before the extract was added to the cultures. 



TABLE VI. 



Later Development and Fate. All the cultures and the controls 

 appeared to reach the 128-256-cell stage at approximately the 

 same time. A reading made four hours and fifteen minutes later 

 showed A retarded, non-motile blastulse; A' blastulse a few 

 motile. In B and B' , there were blastulse, motile in both, but 

 more vigorous in B'. No difference appeared at this stage in C 

 and C', in both of which the blastulse were motile. 



In the readings made on the following day, it appeared that A 

 had stopped at the non-motile blastula stage. In A' were found 

 vigorous gastrulse. In B there were only a very few r blastulse 

 which were moving while B' showed very vigorous late gastrulse. 

 No difference was noted between cultures C and C'. Both of 

 these showed vigorous late gastrulse. 



Conclusion. The cultures containing an appreciable amount of 

 extract exhibited a retardation at the early non-motile blastula 

 stage an effect which was carried over into the later stages also. 



Although the results tabulated above seemed to be practically 

 conclusive, the question arose as to whether it might not be inter- 



