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American Fisheries Society. 24: 
same field to the Duluth Minnesota station in the season of 1904 
resulted in a hatch of but 381 per cent, and while the water tem- 
perature at this place is not known to the writer, it is presumed 
from the geographical location that it is lower than at either 
Put-in-Bay, Ohio, or Erie, Pa. 
We also have a record of 10,000,000 Pike-perch eges shipped 
to Mr. M. E. O’Brien at St. Joseph, Mo., during the season of 
1902 and hatched in water with an average temperature of 54 
degrees, which gave a hatch of 80 per cent. We have still other 
records at the station, all tending in the same direction, but we 
feel that enough has already been given to show that the higher 
the average water temperaure during the period of incubation, 
the greater will be the percentage of eggs hatched. 
During the past hatching season the writer was asked if a 
water temperature of 40 degrees and below was not fatal to the 
egos of the Pike-perch, and while my temperature records showed 
that the temperature had been as low as 39 for several days at a 
time during the season of 1904 and that our hatching record for 
that year showed a hatch of 48 per cent, yet to determine if pos- 
sible how low a water temperature the eggs of the Pike-perch 
would stand, we had seven quarts of eggs placed in a keg, and by 
the use of ice the water temperature reduced to 38 and held at 
that mark for a period of 48 hours, when the temperature was 
allowed to gradually rise until it reached the normal. The eggs 
were then placed in the hatching jars and the same care given 
them. as was given the other eggs, the result was that 12 per cent 
of these eggs hatched, proving that while a water temperature 
lower than 40 degrees is not necessarily fatal, yet it is very 
injurious to the eggs, and we do not doubt but that if the eggs 
have been carried in water of a temperature higher than 40 de- 
grees until after segmentation is well advanced, and then the 
temperature drop to 40 degrees or lower, the result would be 
fatal. However, we have not seen this point tested. 
During the first few days of the past spawning season the 
weather was fine, and the eggs sent in by one of my most experi- 
enced men were of a very good quality. The weather then turned 
colder accompanied by snow and rough weather, and the eggs 
secured by him during this cold snap were nearly worthless. 
Also the eggs secured by others of the force whom I knew to be 
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