314
THE BIOLOGY OF FISHES
_
done for the sea, whether, for example, the North Sea Can
»
be turned into a sort of
“
farm,” with sowing and reapirig
and rotation of crops, or whether such a
quite misleading.
‘
The primary conditions necessary for such an exploit is
' î
some measure of the quantity and quality of the‘organisms
available in the sea, and it is to ViCtor Hensen, the Kiel
.
phy‘siologist, that we owe the rst expression of this vast
idea.
How vast it is we cari only realise when we come
down to details.
Whether such a measure is obtainabl€=br
Î
not, the inuence it has -exerted on the investigations of
the past forty years is one of the most signal examples of = '
_
the power of an idea in scientic work.
When Hensen
put forward his plan in the ’seVenties of the past century v
almostnothing was known of the forms living in the sea,
they could hardly be distinguished from one another at
that time, and, more especially, very little was known
Ï
regarding the eggs and biology of the shes. The eott‘s
__
.?
to realise the plan, however, or to refute its practicability,
have Iain behind m0st
the intensive investigations ”which f
have been-carried out during recent years.
'
.
'
°
"
,
Hensen’s principal aim in the beginning was to determine
the quantities of the plankton in the sea, that is, the small
organisme, plant and animal, whichcan be taken ina net
of convenient size.
Knowing this siZe and drawing the. ;?q:
__
net vertically from the bottom to the surface, the volume of.
..
the Water column could be calculated and hence, from the
î
contents,
the quantity of the organisms in the column.
_‘From many similar columns and the total volume of an
area, let us=say,'the'North Sea, the
quantities of the
'
planktonæùld…becalculated; -
,
…
-
.
'
.
-
ï
':
‘The t€Chnicalî=difcrrltieSï‘-glonç'
of carrying
5
01112 this
are» Very great. ,Nets
are of many different" kinds'ïand. each
.
gives a diereht
picture
of the
if the smallest organisms
7
like the,
are present
_quantities, they
f soon
clog_the
of the" nets
of a column may
'
’
_
really-be“ shed:throug‘h,_
THE BIOLOGY OF FISHES
_
done for the sea, whether, for example, the North Sea Can
»
be turned into a sort of
“
farm,” with sowing and reapirig
and rotation of crops, or whether such a
quite misleading.
‘
The primary conditions necessary for such an exploit is
' î
some measure of the quantity and quality of the‘organisms
available in the sea, and it is to ViCtor Hensen, the Kiel
.
phy‘siologist, that we owe the rst expression of this vast
idea.
How vast it is we cari only realise when we come
down to details.
Whether such a measure is obtainabl€=br
Î
not, the inuence it has -exerted on the investigations of
the past forty years is one of the most signal examples of = '
_
the power of an idea in scientic work.
When Hensen
put forward his plan in the ’seVenties of the past century v
almostnothing was known of the forms living in the sea,
they could hardly be distinguished from one another at
that time, and, more especially, very little was known
Ï
regarding the eggs and biology of the shes. The eott‘s
__
.?
to realise the plan, however, or to refute its practicability,
have Iain behind m0st
the intensive investigations ”which f
have been-carried out during recent years.
'
.
'
°
"
,
Hensen’s principal aim in the beginning was to determine
the quantities of the plankton in the sea, that is, the small
organisme, plant and animal, whichcan be taken ina net
of convenient size.
Knowing this siZe and drawing the. ;?q:
__
net vertically from the bottom to the surface, the volume of.
..
the Water column could be calculated and hence, from the
î
contents,
the quantity of the organisms in the column.
_‘From many similar columns and the total volume of an
area, let us=say,'the'North Sea, the
quantities of the
'
planktonæùld…becalculated; -
,
…
-
.
'
.
-
ï
':
‘The t€Chnicalî=difcrrltieSï‘-glonç'
of carrying
5
01112 this
are» Very great. ,Nets
are of many different" kinds'ïand. each
.
gives a diereht
picture
of the
if the smallest organisms
7
like the,
are present
_quantities, they
f soon
clog_the
of the" nets
of a column may
'
’
_
really-be“ shed:throug‘h,_