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carp than a charr. While some forms deposit their ova in the 
sea, others do so in fresh water, which may be stagnant, semi- 
stagnant, or running. Some eggs are of such a light weight 
that under certain conditions they may float, as of the cod in 
the sea, while those of the herring sink; those of the gar fish 
and its allies are attached by filaments or tendrils to foreign 
substances, while others are likewise adherent, due to a secre- 
tive mucus, as in the lump sucker (Liparis,) which deposits its 
ova on the inside of the valves of dead shells, as a butterfly 
does on a leaf. While the fresh-water bitterling (Rhodeus 
amarus,) of Continental Europe, is furnished with a long 
urogenital tube, enabling it to insert its eggs within the valves 
of the fresh-water mussel. 
Among the curious pipe-fishes the eggs are transferred from 
the female to the male, and in most of the species on the latter 
sex devolves the duty of hatching them, for which purpose 
they are deposited up to the period of the evolution of the 
young in ovigerous sacs variously placed. In the horse-fishes 
(Hippocampus) in pouches under the tail; in our ocean pipe- 
fishes (Nerophis) in rows along the breast and belly. Whether 
this phenomenon of carrying about the eggs is to protect them 
from danger, or change the water in witieli they are kept may 
be questionable, but as these fishes have several times been 
hatched in aquaria, it would seem to be for the purpose of 
protection against foes. Similarly we perceive siluroids (Ariine) 
of the Eastern and other seas in which the males carry about 
the ova in their mouths, either continuously or temporarily, 
and the young may be observed emerging from the ova while 
it is still in the maw of the male fish. Teleosteans, which 
have no oviduct, as the Salmonide, deposit their eggs detached 
one from the other; but such as possess oviducts often have 
them surrounded by a viscid secretion, formed from the lining 
membrane of the oviduct, and agglutinating them in lumps or 
cords. 
Lately Mr Ryper, in the United States, has given some 
interesting accounts respecting the breeding of the catfish, 
another form of sheat fish or siluroid, in an aquarium. A pair 
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