NATURAL HISTORY OF THE QUINN AT SALMON. 
75 
The results were as follows: 
Time eggs had been in water. 
Percent- 
age of 
fertiliza- 
tion. 
Time eggs had been in water. 
Percent- 
age of 
fertiliza- 
tion. 
0.25 minute __ 
98 
4 
0.50 minute 
96 
5 
95 
4 
1.5 minutes 
68 
5.5 minutes 
1 
2 minutes 
57 
6 minntes __ 
0 
33 
6.5 minutes 
0 
17 
i 
17 
7+ 
0 
The susceptibility of ova to fertilization decreases rapidly after they are placed 
in fresh water, and the milt can not be added too quickly. Fifteen seconds is as 
long as they should be in the water before the milt is added, and it is preferable to 
add the milt at the same time that the ova are spawned. 
On one occasion the eggs remaining in the body cavity after artificial spawning 
were removed by cutting the fish open, which mixed them with much blood. They 
were washed as quickly at possible and then spermatized. Only 11 per cent of the 
eggs were fertilized. In another experiment 85 per cent were fertilized in the blood 
without washing it off. 
Effect of exposure to air. — A number of eggs were spermatized after having 
been exposed to the air, temperature 76°, for various periods with the following- 
results, the ordinary method giving fertilization of 99 per cent: 
Time ova were exposed to air. 
Percentage 
of fertil- 
ization. 
12 minutes 
100 
99 
76 
50 minutes 
Apparently there is no injury to eggs by an exposure to the air for half an hour. 
It must be noted that although the eggs were in an open pan they were practically 
immersed in the liquid from the body cavity. 
Fish slime not deleterious. — It is sometimes said that the slime on the fishes is 
fatal to the spermatozoa, and at some stations much care is taken to wipe the fish 
dry before spawning. To test the truth of the supposition, a pan of eggs were cov- 
ered with slime scraped from several fishes, and then spermatized without the use 
of water. Out of 174 eggs examined only two were unfertilized, which is as good as 
is obtained by t he ordinary process. 
Fertilization in body fluid. — At another time, 392 eggs were spermatized “dry,” 
and the milt entirely washed off with normal salt solution before water was added. 
All but six, or 98.5 per cent, were fertilized. This proves that water is not neces- 
sary to excite the activity of the spermatozoa, and that fertilization may be effected 
in the abdominal fluid alone. 
Immersion in normal salt solution. — A quantity of eggs were immersed in 
normal salt solution and at the end of certain periods were taken out and fertilized 
in the usual manner. The results as shown in the table, while as good as could be 
desired, are scarcely better than are obtained by the ordinary method, which gives 
a fertilization of 99 per cent. The value of the experiment lies in the fact that it 
gives us a method of washing bloody eggs without preventing their fertilization, as 
