118 Bulletin Wisconsin Natural History Society. [Vol. 5, No. 2. 
fertilization — were fertilized by spermatazoa immersed for 
twenty minutes in 5%, 8%, 9%, 10%, 11%, and 12% alcohol 
solutions, respectively; in .5%, 1%, 2%, and 5% ether solu- 
tions; and in .1% and .5% ammonium chloride solutions. Of 
these, 25% of the eggs fertilized by spermatozoa, immersed in 5% 
alcohol developed, 1% of the eggs fertilized by spermatozoa 
immersed in the 2% ether solutions ; practically all from the 
spermatozoa immersed in .5% and 1% ether; and none from any 
of the other and stronger solutions. Early in the season, eggs 
sometimes, although rarely, divide (as indicated in Table II) 
after fertilization by spermatozoa immersed in 5% ether. Later, 
several experiments showed no division after immersion in 5% 
ether for ten minutes. 
In Asterias, the relation between a prolonged immersion of 
spermatozoa in weak solutions, and. an immersion in stronger 
solutions for a shorter period of time, becomes quite evident. 
Table IV, p. 119, shows the results of a series of experiments 
carried out to test this relation. 
This table shows that immersion for twenty minutes 
in alcoholic solutions, ranging from 5% to 12%, is fatal 
to the spermatozoa of Asterias, at least as regards their ability 
to fertilize the eggs to which they are added. An immersion for 
ten minutes in solutions above 10%' is also fatal." When immersed 
for one minute, eggs are fertilized from all solutions, except 12%. 
Immersion in 5% ether is fatal for all the periods of time indi- 
cated, and immersion in a .1% solution of ammonium chloride 
for a longer period than one minute, prevents fertilization of the 
eggs by the sperm, as does a .5% solution after all the intervals 
of time designated. 
In all the experiments carried out, abnormal division of many 
eggs was observed after immersion of the sperm in strong solu- 
tions, or in weak solutions for a longer period of time, although 
a larger number of eggs might divide as a result of fertilization 
by such sperm. In one series of experiments, eggs were selected, 
which, normally fertilized, showed a division of practically all 
of the eggs. Very active spermatozoa were immersed in solutions 
