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85
THE BIOLOGYOF FISHES
_» :;
;
are rounded— insection*ànd£dîjäplaya wriggling form of motion,
like the Pipe-shë's and s0me of theelongated Blennies.
Ï°erhaps the most interesting and -instruetive way of
forming & tail is that shown by the Eels: —Here the body is
long,yery muscular and stronglyattened frein side to side.
On eXanning a_éeries‘ of Leptoeephali from about;8 mm.
and onwards Wéhotice that & dark line is graduallyjf0‘rming
_
out in the embryonic n close to the
and under the
itis,ot_diîcultto see that this_line is formed
,
l
from the collection there of
cells.
T h€SÊÏ
can .be _traeed back“th the muscles -ôf :the5'body near the tail;
…
Which _gradually become thiimer
transparent than
the muscles further forward on the body. A study of
_
Plate IX ( I and
Will -sh0iäz'—how the end of the notoehord
the ‘muscle bres at the sides; just
the streaming of the, muscle ;c'ell's t0Wards“:the tip
[
fand oùtOhtothe n
;
.
_,
_
It is evideht:thät the! Vielentïÿniovenients—:oÏ the endi_of
_
,
the tail
thèg muscle “cells outWards,
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_
sand they come ttmn1y1ngfldn thmbryn
n
é—Ïar‘tag‘e;tw0
:
notochord.
The
_
latter fis buthttlebentupwæuds, but=i-spinched o" as usual
andtherodsgrowbaekwards towards the body(Pl. IX,
3,4)t0
of the notoc‘hoi‘d and the dèŸèloping
: neura1and.-hæmal SP—ÎHÇSa
,
_
theothernsdorsalandanalandhavenothmgtodoth Ï
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also, that
,
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archesl
—‘
,
f -_'_Wesee,therefôre,thatmovements and muse—le cells form
"
sh ;
ï'_ :
,*1_ nsar1se - in
'——the ;,s'amç _; way,? :
.IoOSeÿfËfiÏiuS51è
_
i
;eÿen
_
1
theabdormnalregmn The
of : the"
,
"ilsïœlî
fthe-vDogèsh'Phase-_,been.
-
(1906), who, remà1'ks"fthatïever—y »
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