20 



E. E. JUST. 



With cleavage, however, the case is quite different. That is, the 

 per cent, of cleavage of eggs inseminated in a given dilution is no 

 higher than that of eggs inseminated in sea-water and transferred 

 to the dilution before, during, or after membrane separation. 

 There might be a slight indication that eggs exposed during mem- 

 brane separation show a lower per cent, of cleavage. I believe, 

 however, that my figures on this point are not decisive. 



I give now one experiment to show the per cent, of cytolysis 

 in eggs inseminated in dilutions of sea-water as compared with 

 that of eggs inseminated in sea-water and placed in the dilutions 

 before, during, and after membrane separation. 



June 27, 11:25 A.M. Following dilutions prepared: 



Five dishes for each of the six dilutions containing 10 c.c. each. 

 Thus 5 series of 6 numbers each. 



Drops of uninseminated eggs from one female added to dilu- 

 tions as follows : 



Series 1 : 1 drop of eggs in each dilution. 



Series 2 : 1 drop of eggs in each dilution ; inseminated imme- 

 diately. 

 Series 3: Drop of eggs to each dilution 15 seconds after in- 

 semination in sea-water. 

 Series 4 : Drop of eggs to each dilution during the period of mem- 

 brane separation 35 seconds after insemination in 

 sea-water. 

 Series 5: Drop of eggs to each dilution two minutes after in- 

 semination in sea- water. 

 Controls : Uninseminated eggs in normal sea-water ; insemi- 

 nated eggs in normal sea-water. 

 The results of this experiment follow : 

 12 M. 



Series 1: Less than 1 per cent, cytolysis. 

 Series 2: As in Series 1. 



