136 FRANK R. LILLIE. 



constituent of the egg- water is concerned, by finding the greatest 

 dilution at which it will cause visible agglutination in a sperm 

 suspension. If the proportion of eggs to sea-water is about I to 

 4 in bulk, the egg-water from fresh eggs will usually stand dilution 

 to about I/I, 600, and would therefore be accordingly rated as 

 1, 600 units agglutinating strength. Other constituents of the 

 egg-water are diluted at the same time naturally, but there is 

 no present means of measuring these. 



In a preliminary experiment (No. 21) eggs were identically 

 inseminated (one drop of 1:25:7.5 c.c.) in (a) normal sea- water, 



(b) in sea-water to which one part of copper chloride in 500,000 

 parts of sea-water had been added, (c) in egg-water of 1,600 

 agglutinating units to which also one part of copper chloride in 

 500,000 parts of egg-water had been added. In (a) 100 per cent, 

 of the eggs segmented, in (b) none segmented, in (c) 68.5 per cent, 

 segmented. The egg-water was thus shown to protect against 

 the copper chloride. 



More elaborate experiments were then set up, one of which 

 is given in Table IV. Here it is shown that egg-water alone 



TABLE IV. 



(Exp. 23.2.) IDENTICAL INSEMINATIONS IN THE FLUIDS (a) TO (). (One drop of 



i : 25 : 7.5 c.c.) 



Per Cent, of 



Eggs Segmented. 



(a) 1/500,000 Copper egg-water of 400 agglutinating units 5% 



(6) 1/500,000 Copper egg- water of 200 agglutinating tinits 5% 



(c) 1/500,000 Copper egg- water of 80 agglutinating units 50% 



(d) 1/500,000 Copper egg-water of 40 agglutinating units 15% 



(e) 1/500,000 Copper egg-water of 20 agglutinating units 10% 



(/) 1/500,000 Copper egg-water of 10 agglutinating units <o.i % 



(S) 1/500,000 Copper egg-water of 7 agglutinating units <o.i % 



(/?) 1/500,000 Copper egg-water of 5 agglutinating units. . o 



(i) Sea-water alone. Control i 80 % 



(j) 1/500,000 Copper sea-water. Control 2 o 



(k) Egg-water alone (400 units). Control 3 5'^ % 



reduces the percentage of cleavage from 80 per cent, (i, control i) 

 to 50 per cent, (k, control 3) ; that 1/500,000 copper chloride in sea- 

 water completely inhibits fertilization (j, control 2), and that egg- 

 water protects completely against this concentration of copper 

 chloride down to 80 units (a, b, and c), and that its protective 

 action at lesser concentrations falls off to zero (d, e, f, g, h). 



