122 Bulletin yvisconsin yatiiral History Society. [Vol. 5, Xo. 2. 
and 90% of the eggs of the same female divided after an immer- 
sion of the sperm in i % ether. No eggs of Female II divided after 
immersion of the sperm in 10% alcohol, but 5% of the eggs 
divided after the immersion of the sperm in 2% ether; 2% of 
the eggs of Female II divided after the immersion of the sperm in 
0.1% NH^Cl — a larger number than any which divided after 
immersion of the sperm — NH^Cl. 
Table V also shows that a smaller percentage of the eggs of 
Female II divided after fertilization by spermatozoa from Male I, 
than was the case with the eggs of Female I, although the spermat- 
ozoa were immersed in solutions of the same strength and for 
the same periods of time. 
From these results, it appears that inactive sperm can be made 
functionally active by immersion in the above named solutions, 
and that the absence of fertilization in the same cases cannot be 
said to be due to the sperm alone, or, on the other hand, to the 
eggs alone, but to a mutual incompatibility of the two elements, 
even after the spermatozoa have become active. 
SUMMARY: 
Inactive spermatozoa of Asterias or of Arbacia are rendered 
active by immersion in solutions of alcohol, ether, and ammonium 
chloride, in sea-water. In some instances, spermatozoa, thus made 
active, fertilize eggs not fertilized by them before immersion in 
the solutions. 
In Arbacia, strong solutions of alcohol (10% and above), 
produce inactivity in active spermatozoa. A few of the eggs to 
which such inactive spermatozoa are added, divide, but they do 
not reach the later development stages. 
Weak solutions of alcohol (from 1% to 5%) produce greater 
activity in the spermatozoa, and a large per cent of the eggs to 
which they are added, divide. But if the spermatozoa are 
immersed for ten miuntes or longer in these solutions, the devel- 
opment of the eggs fertilized by them is retarded. 
