418 



GRACE MEDES 



per cent 

 fertilization 



Experiment 23 



9 a.m. July 23 



Control 100.0 



9 p.m. July 23 



C9 X Ccf 100.0 



D9 X Dcf 56.1 



9 a.m. July 24 



C 9 XCd^ 100.0 



D 9 X C d^ 3.0 



G 9 XD cf 0.0 



D 9 XD d' 0.0 



D 9 X freshly extruded sperm 3.4 



Freshly extruded eggs XDcf 1.5 



Freshly extruded eggs (used in i) X freshly extruded sperm 



(used in h) 99.7 



The measurements from the various cultures were: 



Both controls, a and j, gave regular growth-curves which 

 agreed very closely with the average for the period in which 

 the experiments were made. As may be seen from the above 

 measurements, when the egg supply and the sperm-suspensions 

 were kept concentrated so that the action of the sea-water 

 was reduced to a minimum, no abnormal effect was produced by 

 delaying fertihzation twelve or even twenty-four hours {h and 

 d). But when the sperm was diluted so that all were in con- 

 tact with the sea-water, a reduction in size of 8.9 per cent was 

 produced {c\. 



After standing 24 hours in the dilute condition, the sperm 

 was more injured than the eggs; for the latter when insemi- 

 nated ^^dth concentrated sperm resulted in a 3 per cent mem- 



