156 
Experiment No. 32.—February 12th, placed six eggs in a 
tumbler of water changed every third day, one hatched March 
27th, one on the 29th, one on the 30th, and one on April 4th. 
It would appear from the foregoing that influences acting 
generally upon a batch of eggs, do not invariably affect each 
single egg in the entire lot to an equal extent, for some are 
observed succumbing at once, others after longer or shorter 
intervals, as from impurities or abnormal temperature of the 
water, or from the effect of concussions. Thus the presence 
of mud or peat may suffocate the embryo by directly stopping 
respiration, or it may not be of sufficient amount to occasion 
this, but by continuously keeping the water thick and deposit- 
ing a sediment on the eggs it may impede respiration where it 
does not entirely stop it, and thus injuriously affect the young. 
But the young as hatched are not all equally valuable, the 
little fish whose time of incubation has been shortened by 
means of raising the heat of the water, is not of that strong 
character as one reared at a lower temperature: the egg kept 
in damp moss, or a tumbler of water, is more likely to give an 
alevin with a rounded yolk-sac and a weak constitution than 
one which has had a full current and an abundant supply of 
oxygen. When raising the alevins, the water has to be deep- 
ened and a fair amount of space provided, or even should the 
progeny live they would most likely be dwarfed, and this great 
requirement for space is one of the reasons of the doubtful 
benefit of incubating eggs of Salmonide in trays placed one 
above another, for even if the young hatch, the amount of tray- 
room will subsequently be insufficient to accommodate all the 
progeny without cramping, and so probably dwarfing the off- 
spring. 
The experiments which I have adduced would seem to point 
to the conclusion that not only the quality and quantity of the 
water, and influences affecting such employed for incubating 
the eggs of Salmonide should be investigated by intending 
purchasers of eyed-ova, but likewise that of the race and 
age of the parents from which they had been obtained; and if 
this is necessary as regards eggs it is still more desirable in the 
