FERTILIZATION AFTER INITIATION OF DEVELOPMENT. 277 



Experiment; Aug. 14, 1916. 



2:30 P.M. Eggs collected and washed divided into lot X and lot Y. 



3:05 P.M. X put into (50 c.c. sea-water + 8 c.c., 2\ m. NaCl). Y put into 

 (50 c.c. sea-water + 16 c.c., 2\ m. NaCl). 



4:25 P.M. Both lots returned to sea-water and lightly shaken to free from 

 jelly, and series of washings begun. 



TABLE II. 



The results of this experiment have been confirmed by a 

 number of others and the results have always been consistent- 

 if the supernatant fluid possessed enough fertilizin to cause the 

 agglutination of a fresh sperm suspension, always there had 

 been eggs present in the culture that possessed enough latent 

 developmental capacity to react with a spermatozoon and to 

 segment as a result of this union, but if no fertilizin could be 

 detected never have the eggs been found to possess a capacity 

 for fertilization. Some change in the physiological or physico- 



1 In every case the numerator of the fraction represents the volume of eggs and 

 sea-water while the denominator represents the volume of eggs and sea-water 

 (in c.c.) remaining in the tube after most of the supernatant sea-water had been 

 drawn off for further details see footnote i on page 276. 



- No larvae produced from 5 P.M. insemination, in either lot X or lot Y. 



