_
MIGRATION OF? FISHES
61-‘
large specimens referred to were from
cm. and more,
:
and,weighed from 4 to, over 81h;remarkable of
is the greàtincrease in thesize of thezeyes. & These become
morethan -four:-tiinestheir former size and weigh twice as
much.
_
ï->Ï
..
Without being able to say positively that such is the
case, one may Conclude that these phenomena point to a great
increase in the internal concentration of salts and absôrption
of Water.
And this increased pressure within seems to be
the cause of the Eel leaving the rivers to seek the greater
pressures of the salt water.
When the impulse to migrate
comes upon them, the Eels are restless and ill at ease”, moving
up and down for a time in a manner quite unlike their usual
.
sluggishness, then denitely turning down the rivets, At
every stage of their descent they come under increasing
pressures without.
And it may be recalled here, that the
Eels are well—known to be extremely sensitive to the
differences Of pressure produced by thundery weather.
=
In the case of marine shes like the Plaice or Cod, we
,
know that when the spawning sh are brought up
trawl, the spawn continues to run even when the shes are—
still alive.This indicates that the
for some time at the level of the de“ep :water whence the.
j
shes came,
Since
low pressure
,
getting rid of the spawn, *the.‘migrati0h"of
'
shallow to deep water would be unnecessarÿÏ'for
-
Hence we may conclude, that an increase of pressure within
'
has occurred with the maturation of the sexual.organs, and
the resulting discomfort has urged the sh to seek deeper , '_
_
water and greater pressures.
Similarly in the case of other-_
shes.
Each species is urged to seek the external conditions, :
.
,
Whether of lower or greater pressure,— wh1chcorreSponds
_
best to the change in.its
;:
I—Ibw far the sh in” its ngratîonSis gmdedlaÿwaÿ
'
_
by its
_
sahth dislsglveîdrgfa$Ê$ÿzetc—a“
'
r‘riàkë f0re—d—ierénëcsïîn;ËË‘SÇSÙŒ: 1ndlversewaY5P°SSIbIY Îîî } Îï
çàs' Hofe1hassuggæœdtheexrremeS€Slb1hty0fthe
lateral
= f
f'
MIGRATION OF? FISHES
61-‘
large specimens referred to were from
cm. and more,
:
and,weighed from 4 to, over 81h;remarkable of
is the greàtincrease in thesize of thezeyes. & These become
morethan -four:-tiinestheir former size and weigh twice as
much.
_
ï->Ï
..
Without being able to say positively that such is the
case, one may Conclude that these phenomena point to a great
increase in the internal concentration of salts and absôrption
of Water.
And this increased pressure within seems to be
the cause of the Eel leaving the rivers to seek the greater
pressures of the salt water.
When the impulse to migrate
comes upon them, the Eels are restless and ill at ease”, moving
up and down for a time in a manner quite unlike their usual
.
sluggishness, then denitely turning down the rivets, At
every stage of their descent they come under increasing
pressures without.
And it may be recalled here, that the
Eels are well—known to be extremely sensitive to the
differences Of pressure produced by thundery weather.
=
In the case of marine shes like the Plaice or Cod, we
,
know that when the spawning sh are brought up
trawl, the spawn continues to run even when the shes are—
still alive.This indicates that the
for some time at the level of the de“ep :water whence the.
j
shes came,
Since
low pressure
,
getting rid of the spawn, *the.‘migrati0h"of
'
shallow to deep water would be unnecessarÿÏ'for
-
Hence we may conclude, that an increase of pressure within
'
has occurred with the maturation of the sexual.organs, and
the resulting discomfort has urged the sh to seek deeper , '_
_
water and greater pressures.
Similarly in the case of other-_
shes.
Each species is urged to seek the external conditions, :
.
,
Whether of lower or greater pressure,— wh1chcorreSponds
_
best to the change in.its
;:
I—Ibw far the sh in” its ngratîonSis gmdedlaÿwaÿ
'
_
by its
_
sahth dislsglveîdrgfa$Ê$ÿzetc—a“
'
r‘riàkë f0re—d—ierénëcsïîn;ËË‘SÇSÙŒ: 1ndlversewaY5P°SSIbIY Îîî } Îï
çàs' Hofe1hassuggæœdtheexrremeS€Slb1hty0fthe
lateral
= f
f'