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are deposited ; still they are treated either by being laid on the 
bed of the stream or below the gravel, but the pisciculturist 
has ascertained that this placing them within a bed or nest is 
not essential to the hatching of any of these forms. 
Before passing on from the eggs and how deposited, I must 
draw attention to a rather curious phenomenon, but too often 
seen, and which in its most fatal form is known as fish being 
egg-bound—dying, in fact, unable to void their ova, similarly 
to fowls unable to lay their eggs, or higher vertebrates which 
cannot bring forth their young. Some fish, as the herrings, 
which exude their ova in the open sea, can scarcely be 
subjected to any extraneous force in order to assist this 
process, but that such does take place in some fishes has been 
ascertained. The gold carp (Carassius auratus) is one of these 
forms, and the male (or rather relays of them) have been 
observed in an aquarium to roll the gravid female like a cask 
along the bottom of the tank, and to continue this operation 
without relaxation for a day or two until the wearied female 
has extruded her ova. The female river lamprey is said to 
be assisted by the male twisting himself around her, and so 
expressing the ova and milt, the suctorial mouths of both 
parents being at this time attached to a stone or other suitable 
stationary object. While it does not appear unlikely that the 
female salmon or trout, when forming the redd or nest by 
lateral strokes of the side and tail portion of the body, is by 
such active exertion assisting in ridding herself of her eggs. It 
has been asserted that among these latter fish, when the eggs are 
ripe there is no power to prevent their escape, but at Howietoun 
it is found that if the parents are placed in a wooden tank, 
having smooth sides and bottom, and through which a stream 
flows, ovulation may be deferred days and even weeks. 
But even when fishes’ eggs have been deposited it does not 
follow that it is only necessary, in order that they should hatch, 
to place them in a hatching box, turn salt water over marine 
ones and fresh water over those of our streams and lakes. 
The precautions to be taken by the fishculturist I do not 
propose alluding to, but certain physical phenomena are very 
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