52 
these eggs which should prevent their adhering to one an- 
other, without its being necessary to resort to stirring or 
other mechanical agitation. 
One method that has been pursued is to allow the eggs 
to lie in the water in which they are fertilized. Such water 
is milky from the large number of spermatozoa which it 
contains, and is also quite strongly alkaline. 
Eggs left in the water do not adhere, and after having 
lain in the milted water for two hours they may be trans- 
ferred to fresh water, and will usually not then adhere. 
This would then seem to be a solution of the difficulty, 
but some experiments which I have made, and which are 
published in the Tenth Report of the Michigan Fish Com- 
mission, show that when eggs are treated in this way many 
of them fail to absorb water and remain of smaller size and 
softer than normal eggs. Such eggs do not afterward de- 
velop. The method is, therefore, not practicable. 
It seemed that the result sought might be accomplished 
in any one of three other ways. 
1. Some substance might be dissolved in the water, 
which, without injuring the egg or spermatozoon, might 
still so act on the external egg membrane as to destroy its 
adhesive properties. It is known that the spermatozoa 
live in weak solutions of various substances and that eggs 
are not readily killed by many such solutions. A consid- 
erable number of such substances was tried in very weak 
solution. Among them were common salt, chromic acid, 
chromic acid combined with salt, ammonium hydrate, 
potassium hydrate, sodium carbonate, sodium sulphate 
and egg albumen. But the experiments were fruitless, 
and it is not necessary to detail them here. A mixture of 
salt and chromic acid destroys the adhesion of the eggs 
permanently, but the spermatozoa do not live well in it, 
and the egg does not fill after its action. 
2. It might answer to allow eggs to adhere to one an- 
other in a mass and afterwards to separate them by me- 
