THE SEABOTTOM
.,73
It might appear. at rst sight as though thisknowledge
_
was of quite Secondary importance and not worth the very
.
great labour its collection undoubtedly entails.
But this is
farirom being the case.
Wehavealready referred'tothe
unity of life, and hereis an example ;. the
_
especially the shellsh and worms, form the most important
part of the food.of-the bottom-living sh; such as the different '
‘
at-sh, the skates and the;haddock,and it has been shown
by the Danish investigators that the success or failure of the
-
sheries in any year is largely dependent upon the. numbers
of other members ot the bottom fauna, especially shellsh,
in that year.
On the other hand the prevalence ofstarsh
has just the opp05ite effect for
animals—from the
'
sherman’s point of view—are pests,__pure and simple, they
are of no use to man while they destroy couness. numbers
of shellsh.
'
-
-
m'
».
.
;
,
ADAPTATIONS
'
.
_
‘
_
_
Different animals are adapted for life ”under different
"conditions, and the bottom—living aniamls possess man-y
_
structures and— peculiarities which t themî for life on the
sea bottom.
Wehave already spoken of the manner in.
which burrowing animals
connection with the
surface, while in Chapter IX we shall see Something of their
'
devices for obtaining food.
There is also; the vital matter
—
of reproduction.
Very many. of them,produce eggs which
batch out into animals totallÿ’unlilre their parents… «Star—
.
sh and their relatives provide the most striking examples of
this, but worms and crustaceans affordinstances. almost as
(compare the adult crab in Plate 14 with the young
'
of the same species shown-inPlate 43). These “larvæ” do not
.
stay at the bottom but rise. towards the surface,.where‘ they
are for a time part of the drifting life, described
-
'
and only settledown'toth'e- hùmdrum
life-of the'1rŒparente
.,73
It might appear. at rst sight as though thisknowledge
_
was of quite Secondary importance and not worth the very
.
great labour its collection undoubtedly entails.
But this is
farirom being the case.
Wehavealready referred'tothe
unity of life, and hereis an example ;. the
_
especially the shellsh and worms, form the most important
part of the food.of-the bottom-living sh; such as the different '
‘
at-sh, the skates and the;haddock,and it has been shown
by the Danish investigators that the success or failure of the
-
sheries in any year is largely dependent upon the. numbers
of other members ot the bottom fauna, especially shellsh,
in that year.
On the other hand the prevalence ofstarsh
has just the opp05ite effect for
animals—from the
'
sherman’s point of view—are pests,__pure and simple, they
are of no use to man while they destroy couness. numbers
of shellsh.
'
-
-
m'
».
.
;
,
ADAPTATIONS
'
.
_
‘
_
_
Different animals are adapted for life ”under different
"conditions, and the bottom—living aniamls possess man-y
_
structures and— peculiarities which t themî for life on the
sea bottom.
Wehave already spoken of the manner in.
which burrowing animals
connection with the
surface, while in Chapter IX we shall see Something of their
'
devices for obtaining food.
There is also; the vital matter
—
of reproduction.
Very many. of them,produce eggs which
batch out into animals totallÿ’unlilre their parents… «Star—
.
sh and their relatives provide the most striking examples of
this, but worms and crustaceans affordinstances. almost as
(compare the adult crab in Plate 14 with the young
'
of the same species shown-inPlate 43). These “larvæ” do not
.
stay at the bottom but rise. towards the surface,.where‘ they
are for a time part of the drifting life, described
-
'
and only settledown'toth'e- hùmdrum
life-of the'1rŒparente