78 MARVELS OF FISH LIFE 
the eggs are placed under taps from which the water is 
allowed to run slowly into them, so that the water in 
the jars is gradually brought to the temperature of the 
water in the hatchery. Any sudden change in the tem- 
perature of the water containing the eggs would be 
fatal. When hatching salmon alevins from which the 
photographs were obtained, as shown in the earlier part 
of this chapter, I well remember my groom suddenly 
turning on the cold, town water supply, with the result 
that out of some two hundred alevins only thirty or 
forty were saved. After the water has been changed 
and the eggs washed in the process, the eggs are laid 
down either in baskets, or on glass grills to undergo the 
first period of incubation. 
While incubation proceeds, the eggs are daily 
examined, and all the dead eggs picked out with a glass 
pipette. 
In seventeen to thirty days, according to the tem- 
perature of the water, the eggs can be moved without 
fear of injury. The trays are now placed in a shallow 
basin in a good light, and every egg which does not 
contain a fish is removed. The remaining eggs are next 
carefully washed and measured, and are then ready for 
the packer. 
Different forms of packing cases are in use; those 
used by the United Fisheries Company consist of wooden 
eases, Which have receptacles for ice at the ends and 
in the lids. Inside the case are arranged numerous 
shallow trays filled with moss. The moss is covered with 
