132
,
THE '"BIOLOGY OF FISHES
in water,into their digestive tract or air—sacs, and it was just
_
'
this mode of re$piration that led to the appearance of the
'
air—bladder.
_
,
_
‘
.
The Teleosts thus show two primitive modes of respira—
'
’
,
tion and this fact, taken with their feebler circulation, helps
'
,
!
us
to
understand the differences in their organs and
structures from those of the other groups.“
.
=
Hæmoglobin, a complex chromoproteid, is always
present in the blood corpuscles of the adult shes and higher
animals.
How it is formed, we do not precisely know, but
'
the head—kidney has Something to" do with its formation
(Reuter). These corpuscles are oval in shape, biconvex
and nucléaæd {except in Cyclostomes). The hæmoglobin
.
Within the
of carbon, oxygen, nitrogen,
'
,
a small .percentage of sulphur and iron.
'
Its—;‘peCuli-ar—
an attracti0n for oxygen,
;'
but this attractionis
from
"
neighbouring media, w—hiCh_
pressure
'
Î
of oxygen, and gives it uptO Cells With less.
,
unfortunaté thing is, that other gasès have also anaîmtyfor
Ÿhæmoglobin, more particularly carbon monoxide Withan
’
'
attraction 140 times greater than. that of oxygen. These
therefore, readily displace the oxygen, and
"
very few cells or organisms can live without oxygen.
.
',
_
,
With the appearance of hæmoglobin and the formation
,
of denite blood-vessels, a division of labour takes" place
:'
'
[between the blood and the ;__*l_ymph.:e Theredblood
_'
:
corpuscles keep rtoçâthe
the
of
"
: ï '
resp1ratron,whst ï{the : _ lyrÏ1ph only
_.
'a
—_ watching brief
'
'
:
1nthrsrespectandconcentrateson the feeding and cleansing
'
oftheœns
,
_
: The il'euco'cytes fare far ,outhumbered in the blood by the ’
.rëd blood'corpùscles,‘ butthey are the,main bodies in the
lymph and lymphoidoi‘gans. They are mobile like the
;
Amœba and have -many diverse functions. For. eXample, »
:
it is only by their aid that
are transferred' from the
"
_—%f
the' lymph, ander this
,
“between the other cells, Which'arè: busy 'abSQrbing
g_“'
,
THE '"BIOLOGY OF FISHES
in water,into their digestive tract or air—sacs, and it was just
_
'
this mode of re$piration that led to the appearance of the
'
air—bladder.
_
,
_
‘
.
The Teleosts thus show two primitive modes of respira—
'
’
,
tion and this fact, taken with their feebler circulation, helps
'
,
!
us
to
understand the differences in their organs and
structures from those of the other groups.“
.
=
Hæmoglobin, a complex chromoproteid, is always
present in the blood corpuscles of the adult shes and higher
animals.
How it is formed, we do not precisely know, but
'
the head—kidney has Something to" do with its formation
(Reuter). These corpuscles are oval in shape, biconvex
and nucléaæd {except in Cyclostomes). The hæmoglobin
.
Within the
of carbon, oxygen, nitrogen,
'
,
a small .percentage of sulphur and iron.
'
Its—;‘peCuli-ar—
an attracti0n for oxygen,
;'
but this attractionis
from
"
neighbouring media, w—hiCh_
pressure
'
Î
of oxygen, and gives it uptO Cells With less.
,
unfortunaté thing is, that other gasès have also anaîmtyfor
Ÿhæmoglobin, more particularly carbon monoxide Withan
’
'
attraction 140 times greater than. that of oxygen. These
therefore, readily displace the oxygen, and
"
very few cells or organisms can live without oxygen.
.
',
_
,
With the appearance of hæmoglobin and the formation
,
of denite blood-vessels, a division of labour takes" place
:'
'
[between the blood and the ;__*l_ymph.:e Theredblood
_'
:
corpuscles keep rtoçâthe
the
of
"
: ï '
resp1ratron,whst ï{the : _ lyrÏ1ph only
_.
'a
—_ watching brief
'
'
:
1nthrsrespectandconcentrateson the feeding and cleansing
'
oftheœns
,
_
: The il'euco'cytes fare far ,outhumbered in the blood by the ’
.rëd blood'corpùscles,‘ butthey are the,main bodies in the
lymph and lymphoidoi‘gans. They are mobile like the
;
Amœba and have -many diverse functions. For. eXample, »
:
it is only by their aid that
are transferred' from the
"
_—%f
the' lymph, ander this
,
“between the other cells, Which'arè: busy 'abSQrbing
g_“'