132 FRANK R. LILLIE. 



membrane reaction. The membranes of such eggs are "narrow," 

 or better, the perivitelline space separating egg and membrane 

 is narrow, often extremely so, down to the point of invisibility. 

 The viability of such eggs is bad even if they are returned to 

 sea-water again within a few minutes (Table III.). Indeed, the 

 viability forms an ascending series to normal from 10 seconds 

 up to 5 minutes. In other words, the fertilization reaction 

 exhibits gradation in intensity according to the point of 

 time at which the copper begins to operate, reaching normal 

 at about two minutes with the best lots of eggs, and viability is 

 proportional to fertilization intensity. There is no recovery 

 from an initial subnormal reaction. 



TABLE III. 



(Exp. 37.) EFFECTS OF COPPER CHLORIDE ON EGGS INSEMINATED IN SEA- 

 WATER. Insemination, one drop of 1:5:5. Eggs replaced in sea-water after 

 14 minutes' exposure to CuCh. This experiment came at the end of the season 

 when the eggs were not in first class condition. 



Transfers to Per Cent. 



1/500,000 CuCh. Segmented. Remarks. 



(a) 10 seconds after insemination 15% 



(6) 20 seconds after insemination 30% 



Membranes "narrow." 

 Viability bad. 



(c) 25 seconds after insemination 30% 



(d) 40 seconds after insemination 50 % + 



(e) 60 seconds after insemination 60% ) Membranes "narrow." 



(/) 90 seconds after insemination 70% j Viability better. 



(g) 2 minutes after insemination 80% Viability still better. 



Not equal to control. 



(h) 5 minutes after insemination 80 %+ 1 



(?) 10 minutes after insemination 90% j Equal to control. 



The period of time involved in these subnormal effects is that 

 of membrane formation or of cortical discharge. 



We have, thus, three distinguishable effects of copper chloride 

 at successive stages of fertilization :. 



1. To inhibit activation if present at insemination. 



2. To reduce the intensity of the cortical discharge, if its 

 action begins within the first two minutes, proportionally to the 

 time of its operation. 



3. A slow cumulative injurious effect thereafter which belongs 

 to a different order of events from I and 2, and which does not 

 become obvious until late cleavage. 



