53 
chanical means, such as passing them through a sieve. 
This method has been pursued, as I learn from Mr. Stran- 
ahan, at the United States hatchery at Put-in-Bay, Ohio. 
A trial showed that the eggs when separated are dis- 
torted by the mutual pressure. Some are elongated, others 
are flattened, and scarcely any are spherical. About 10 
to 15 per cent. more of the eggs are injured mechanically 
than by the process next to be described. 
3. It might be possible to add to the water some sub- 
stance that should get between the eggs and prevent their 
touching one another. It was believed that the reason 
that the eggs did not adhere in milted water is that the 
heads of the spermatozoa attach themselves to the surfaces 
of the eggs, and thus so thickly studded with these little 
bodies that they cannot touch one another, and do not 
therefore adhere. 
The alkalinity of the milt prevents the eggs from filling, 
and it was thought that perhaps some other finely divided 
substance not alkaline might be placed in the water to 
take the place of the milt. Trials were made of egg yolk. 
After fertilizing the eggs they were placed in water con- 
taining egg yolk in a finely divided condition. The eggs 
did not adhere, but they did not develop. Fine clay mixed 
with water was also found to be useless. The egg yolk 
probably failed through some chemical action on the eggs 
or milt. It seemed likely that the failure of the clay was 
to be attributed to the fact that the fine hard particles cut 
their way into the outer egg membrane and became so 
deeply imbedded in it that the eggs were able to touch 
one another and adhere. 
Corn starch was then tried. About one volume of dry 
corn starch was added to 20 volumes of water. The eggs 
were fertilized in the usual way, and were immediately, 
after two or three minutes, poured into the starch water. 
Another lot of eggs was then fertilized and added to the 
starch water, and the work was continued until the pail 
