NATURAL HISTORY OF THE QUINNAT SALMON. 
77 
of fungus if they are not removed. It was found by counting the number of broken 
eggs in several lots spawned in the ordinary manner that they averaged nearly 1 per 
cent of the entire take. 
In the ordinary method of expressing the eggs they leave the oviduct under 
considerable pressure and strike the spawning pan with as much force as if they 
had fallen several feet. This manner of spawning, as already seen, breaks nearly 1 
per cent of the eggs, and there may be many among those not broken that are 
injured; this may account for the heavy loss of the first day in the hatching-house. 
Dry process of fertilization. — The method of fertilization used at Battle Creek 
in 1897 and 1898 was to spawn the eggs into a pan containing a little less than a pint 
of water, spermatizing them at the same time. They were then allowed to stand 
about 2^ minutes, when they were poured into a large bucket and gradually washed 
by adding fresh water. Basket No. 6 of the table given in the notes below on the 
critical period experiment was treated in this manner. The eggs of basket No. 5 
were fertilized without any water, but otherwise were treated the same as No. 0. 
There was a difference of only 0.3 per cent in fertilization. There was a difference 
of 0.2 per cent between baskets No. 6 and No. 7, and they were from the same fishes 
and treated in the same way, so far as fertilization was concerned. 
The method used at Battle Creek seems the better, as the eggs can be mixed with 
the milt more easily. A half minute, or just long enough to mix the eggs thoroughly, 
is an abundance of time for them to remain in the spawning-pan. 
Killing the female before spawning. — It has been claimed by some fish-culturists 
that killing the female before spawning causes deformed fry. Basket No. 1 (see 
table on p. 79) contained eggs from fishes killed by a blow on the head. There were 
not even so many deformities in it as in others. This method of procedure is not 
recommended, however, as green fishes would sometimes be killed, and their eggs 
therefore lost. 
Quality of bloody eggs. — Occasionally a female has been injured before spawn- 
ing, and the eggs when pressed from the body were mixed with blood. Eggs from 
three such fishes were kept separate; 7.7 per cent of the eggs died within five days; 
of the remainder, 2 per cent (3 out of 154) were unfertilized. The fertilization was 
about as good as the average, and a small amount of blood seems not to be detri- 
mental to fertilization. Several females were opened after spawning, and the 
eggs remaining were removed. The eggs were mixed with a great deal of blood, 
and only 85 per cent could be fertilized, so that a large amount of blood is detri- 
mental to fertilization, probably because clots of blood prevent thorough mixing 
with the milt rather than from any injurious effect upon the ova or spermatozoa. 
Foamy eggs. — Often the ovarian liquid becomes foamy as the eggs are spawned. 
It was not known whether such eggs were fertilizable. In the foamy eggs experi- 
mented with 99 per cent were fertilized. 
Granular eggs. — The eggs from a certain small salmon, owing to the arrange- 
ment or superabundance of oil globules, had a peculiar granular appearance. Fer- 
tilization by ordinary process was 99 per cent; apparently healthy when 26 days old. 
Eggs dead when spawned. — Occasionally eggs at the time of spawning have a 
dull, yellowish appearance, and are evidently not healthy. They are always thrown 
away. Eggs of this kind from one fish were kept. Seventeen days after spawning 
30 per cent had died, and of the remainder 23 per cent were unfertilized. They 
were not kept for further observations. Such eggs were not found in 1898. 
