'
ECONOMY ,OF 1THE’
131
,
and becoming aerated, reCeiving oxygen and giving up
'
carbonic acid,in the gill laments, itis collected again into J
a single dorsal aorta. v From this branches are given off to '
…
the head, brain,; and
theri'_it passes"
backwards beneath the vertebral; Column: ÉQ'SUpPÏY'ÎhÔbÔdY. : ; '
The secret of
_
the differences 'betweenç'thef'Various 'shes f'
_
and between these
' . and the
sought in the blood'and ly1nph._ç
body,
,
organ tothe
are, bathèd in
,
,
uids which
and out,-leaving
,
"
selected by the, cells ;and- carrying aWay, the «ifproduets" the
cells want to ;get rid of. ,
even withihf one. and ,the
"
’
same
are,Verÿ dierent
.
poison
others, The cells,therefore have the power of
selecting and Separating the, materials. When this power
' '
'
ceases the cells perish and have to be removed ;_ otherwise
,
the body will die.Ï
‘
_
_»_' -,
,
…
'VSÏlien peOple,say; that _‘=‘ the blood is
they
:
'
,
usually—mean, the red blood, but this is an err0neoushoti6,
,
Ï
lymph is the pnn01pal
‘
-
as1twasthe originalïblood.» :,Thè:shtæs provide. us
,
'
Importantlessonsmthlsrespect Amphioxushas.
-_
'
b1dthyngEl ’
have a
'
some
larval ,Clupeids
,
'
"_
'
days after they are,hatch«èd. The Other. groups‘of- shes‘,
’
'
_
'
however, are well supplied with red blood from an early
,eränbryonic stage.
'
The lymph is a saline, aqueous solution containing
_
albuminoids and other substances.
Some of thealbumi—
'
,
contain a colduring
=
}'.f
certain amount of
respirati0n. But
_
not‘ag_necessity…z .:Insects aregable, todo wrthout1t,simply
bth bhg …æ ythxygnày
«to
cellsz,Ï- ’Many ;Teleostsgmake useofthmpnmwe
'
dfptnhnthymthgdld=