E. E. JUST. 



segment. The observation of July 20 may serve as a typical 

 case. 



At 10:10 A.M., dry Echinarachnius eggs were placed in sea-water; total bulk of 

 eggs plus sea-water equalling 10 c.c. (Lot A.) 



10:20 A.M., 10 c.c. of ovaries plus 90 c.c. of sea- water were placed in a cylinder 

 which was gently inverted three times. (Lot-B.) 



10:50 A.M., 7 c.c. of sea-water removed from eggs of Lot A filtered and diluted 

 as follows: i/io, 1/20, 1/40, 1/80, 1/160. 7 c.c. of fresh sea-water added to eggs. 

 Trials with sperm of two males gave a 6-second reaction at 1/20. 



11:20 A.M., 6 c.c. of supernatant sea-water removed and filtered, dilutions 

 being made as before. (6 c.c. of fresh sea-water added to eggs.) 4~(?)-second 

 reaction at i/io dilution; very faintly positive. 



11:50 A.M., 5 c.c. of supernatant sea-water removed and filtered with dilutions 

 as before, 6-second reaction at i/io. Eggs inseminated 3:00. These normally 

 fertilized eggs show very few cleavages. Lot B gave comparable results. 



If this were a long series of washings extending over two or 

 three days, one might suggest that these eggs no longer fertilize 

 or give the agglutination test because they are dead. One could 

 scarcely have the hardihood, though, to venture that the eggs 

 die after remaining in sea-water some ninety minutes. Rather 

 these eggs fail to fertilize, as was discovered during the next two 

 days because of some membrane condition, for on the addition 

 of ether to the sea-water, eggs, of which but i per cent, showed 

 cleavage in normal sea-water, gave 90 per cent, cleavage and 

 normal larvae. I might designate these eggs as over-ripe fol- 

 lowing R. S. Lillie's usage since they behave so much like over- 

 ripe A sterias eggs. The cleavage percentage of these eggs is always 

 low and their agglutinin production feeble. Unfortunately, 

 I failed to study the agglutinative power of these ether-treated 

 eggs. 

 4. Fertilizin Production After Membrane Formation. 



Observations on eggs with membranes which were not made 

 before the season of 1918 show that after insemination or 

 successful butyric acid treatment fertilizin production ceases. 



(a) Eggs with Fertilization Membranes. Lillie found ('14, pp. 

 553-557) that in Arbacia fertilized eggs with jelly removed by 

 shaking ceased to give the fertilizin test after five washings 

 (extending over a period of one hour and forty-three minutes), 

 the last washing being made at two hours and twenty-three 

 minutes after insemination; while an equal quantity of eggs of 



