THE HABITS OF FISHES
33
_
…
On the east coast of Scotlandthe passive drift of the
eggs of Plaice and othershes has been studied by Fulton
'
by means of oats or drift-bottles set free at the grounds
'
where the species were known. to be spawning: These
'
bottles passed down—the coast from oAbàdeenshire towards
the south; some of them _stranded—on thecoast, biit quite a
'
number drifted across the North Sea, in its northern part,
and landed on the Danish coast, some even reaching Norway“.—
The Plaice eggs, however, take only about three Weeks to
hatch out, and in that time the drift bottles had only reached
as far as the southern counties of Scotland, and there could
be no question of the eggs 0r-fry crossing the North Sea.
‘
In fact,_…the young Plaice are foünd, some three to four
’
months after the eggs are spawned, all along the margin of
'
in shallow water.
'
'
'
'
,
..
Î
=
;There is a {Certain correspondence therefore betWeen
'
currents and the drift of the earliest stages,
'
butiwhen we look more closely into details the coesp0ndence
becomes less
_Thus, other:sh eggs"are also'in._the
'
same drift—Cod, Hadddclç, Long—rougir; Dab,
'
the
species ate never found-on the shore.
’
ati—some time 'düfihg
Stages fthe
‘
j
d1fferent species
from“ ' one%_ another and :go '_Îh'€if
'
several waysWhenthlsseparatwnls eeëæd and by what
means
16
'
'
Several fact0rs are
'_Firstly,
the eggs, as the embryo - within absorbs rthe ghter yolk,
increase in density and tend to sink down from the surface ;
hence, they are no limger under the inuence of the surface
drift.
A great deal, however, depends on the prevailing
temperature;_ if this is high the eggs seem able to eXpand
'
'
and thus do not sinl; even: when the density-of . the water
,deè‘reases …(Iohanseri, Strodtmam‘1).p Thuss the :'iratelof' ,
'
::;deyçlopment of the
nature of theyolk,andthe _'
'
_
ethernal c0nditions of temperatureanddensity, auœmeintd
,
,
the separation ' of the developing eggs ofd1fferent
'
of the
.
.
Sé:eondly,=ÎWhé
escapegf'rom
;' eggs,‘
_
,
.
.'
-
.
.
'
'
33
_
…
On the east coast of Scotlandthe passive drift of the
eggs of Plaice and othershes has been studied by Fulton
'
by means of oats or drift-bottles set free at the grounds
'
where the species were known. to be spawning: These
'
bottles passed down—the coast from oAbàdeenshire towards
the south; some of them _stranded—on thecoast, biit quite a
'
number drifted across the North Sea, in its northern part,
and landed on the Danish coast, some even reaching Norway“.—
The Plaice eggs, however, take only about three Weeks to
hatch out, and in that time the drift bottles had only reached
as far as the southern counties of Scotland, and there could
be no question of the eggs 0r-fry crossing the North Sea.
‘
In fact,_…the young Plaice are foünd, some three to four
’
months after the eggs are spawned, all along the margin of
'
in shallow water.
'
'
'
'
,
..
Î
=
;There is a {Certain correspondence therefore betWeen
'
currents and the drift of the earliest stages,
'
butiwhen we look more closely into details the coesp0ndence
becomes less
_Thus, other:sh eggs"are also'in._the
'
same drift—Cod, Hadddclç, Long—rougir; Dab,
'
the
species ate never found-on the shore.
’
ati—some time 'düfihg
Stages fthe
‘
j
d1fferent species
from“ ' one%_ another and :go '_Îh'€if
'
several waysWhenthlsseparatwnls eeëæd and by what
means
16
'
'
Several fact0rs are
'_Firstly,
the eggs, as the embryo - within absorbs rthe ghter yolk,
increase in density and tend to sink down from the surface ;
hence, they are no limger under the inuence of the surface
drift.
A great deal, however, depends on the prevailing
temperature;_ if this is high the eggs seem able to eXpand
'
'
and thus do not sinl; even: when the density-of . the water
,deè‘reases …(Iohanseri, Strodtmam‘1).p Thuss the :'iratelof' ,
'
::;deyçlopment of the
nature of theyolk,andthe _'
'
_
ethernal c0nditions of temperatureanddensity, auœmeintd
,
,
the separation ' of the developing eggs ofd1fferent
'
of the
.
.
Sé:eondly,=ÎWhé
escapegf'rom
;' eggs,‘
_
,
.
.'
-
.
.
'
'