and on the SalmoyuFishei'ies. 
34S 
ga against the tide i” p. 44. “ They run backwards and forwards with the tide 
in all directions p. 45. Mr Hailiday admits that it is common “ for salmon to 
ebb and flow with the reflux of the tide p. 91. With these admissions, the 
two last witnesses consider the salmon taken in stake-nets, with an ebb court for 
taking fish with the ebb tide, were such as had been in the river or estuary, and 
were leaving it for the sea. But if the salmon were innotwe^ the motions of the 
ebb-tide would carry them into the nets, in the same manner as the flood-tide 
carried them past. The fish do not enter rivers until the water is in a 
■state to receive them, and they are in a condition to enter. Hence, on the 
shore and in estuaries, when not inclined to migrate, the motions of the tide 
will control them, and the ebb-nets, wiU, from their very nature, he most 
likely to secure them. Even in the driest seasons, when the fish were not en- 
tering the river, Mr Halliday states that the ebb-nets were most successful ; 
p. 72. Could they be other fish than such as passed by with the flood ? 
If fresh waters be so exhausting to salmon, and promote the growth of pa- 
rasitical maggots so rapidly, how comes it to pass that they ever leave the sea, 
unless for the necessary purposes of spawning ? The three witnesses, who 
consider that salmon run out of rivers to get rid of the worms which infest 
their giUs, have a similar hypothesis for explaining their leaving the sea. Mr 
Johnstone says, in reference to their visits to rivers, “ One evident object is 
to get clear of the vermin termed the sea-louse^ which infests them sometimes 
when in the sea, and which leave them when they get into fresh-water;” and he 
admits, that when the salmon are subject to this insect in the sea, they are in the 
highest condition ; p. 35. In reference to the length of time the sea-louse re- 
mains upon fish after leaving the sea, he observes, I do not think it remains 
many days; for when they are in the fresh-water, we soon observe them to go 
off ; they do not go off all at once, they go off by degrees ;” p. 53. Mr 
Halliday says, “ They visit rivers to clean themselves of the sea-louse, an in- 
sect that fastens to them in the sea, and with which they are infested when 
they come out of the ocean, but which die in the fresh water ;” p. 61. Mr 
Little says, ‘‘ It is instinct which induces them to return to the rivers, and, 
as I consider, for the purpose of getting rid of a vermin v/hich gets upon them, 
called sea-lice;” p. 108. The animal here referred to is the Mmoculm piscinus 
of Linnaeus, and the Caligus curtus (mixed probably with C. productus) of Mul- 
ler, but usually confounded with tiie Lerncea salmonea of Linnaeus, by a blun- 
der of Mr Pennant. This animal is common to the salmon, whiting, cod, and 
flounder. The three last do not enter rivers to escape from its attacks. The 
salmon, when most infested by it^ is in the fattest and healthiest condition ,• but still, 
in order to have it removed, this fish, in the opinion of these witnesses, enters 
rivers, where it is certain of being exhausted in a week or ten days, and where 
it is in danger of having its organs of respiration entirely devoured by the en- 
toraoda or maggot. Another reason assigned by the same witnesses for sal- 
mon entering rivers, is searching for food. Of this, however, no proof is offer- 
ed. But, in reference to estuaries, Mr Halliday has taken a great many sal- 
mon, “ with worms passing through them ; such worms as are to be seen on 
the banks;” p. 61. ‘‘I have had thousands of them dissected, when I have 
.seen small sea-fish in their stomachs ;” p. 90. 
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