REGULATION OF
97
forward,
body becor'nesjdéepe ,and the head ;;
larger. Wè ma}? say, that the centre of balance Or 'gravity
is moved forward, With a” greater?coucèntratio?bfŒhebody
substance 'anteriorly, and this again leads to a change in the
mode of
'
»
'
Whilst the
the gut hgvé-äpf6bablyÏ,béen the
principal factor
alterig the dispositionbf
tWo;—other factors have to» be
The àÏr—i
blgddéÿ—ïîth€'fTelegsts h_âs begun iri'à posterior positionèand
obliged=to move—.f0rward with the gi1t,:,thus
inuencing the mOve‘ments and, balanceb£ the structures;
Its inuence in a special case Will be
itmaÿ_
».
be noted—tlîät in
(Fig. ___23, 4), Where it remains
post’eriorly,‘ the-.:Ven‘tral ns, develop underneath, thus
abdominally, îvhereas in the other specialised formsgured
they develop
(“Big. _23, 7). In the Dippigri‘dsome
Teleosts the air-bladder isëîiiery long,
,
gùllet back toxyärds the tail, gmd the body also remäië
;;
elongated.
"
_
,
The third faétor affecting the movements and shape Q£the body has been the formation of
mouth.
,
This has
_
been._a
Will be described
,
below: In mânÿ;casfes‘,{it appears, the young larvæ
-
:
work hard for
-.
_.
of“ the
therelat1ve
_.
proportionsofthed1erentregionsandmmovmgfonvard -
,
,
'
thegut a'nïd air—bladderhavethusledtothechangeofferm
'
.
?
:
3hd struCture âm0ñg thé
'
',
.
the larvà _to
,
-
this seems:
beenthe
=QfÏ
;
However symméëricàl abodymay
be»ng
,
' -
tQ=.'move‘it
‘
'
-;
resistahœsÊiof
“
>
3.1t;hëàîfæter, it:- tries ;;:_œJ move :the_s v@$e these1nvoluntary
; Ï
become.
__
,Î È
Î=ÏÏ
_
'
f
iÏf ï—fË;—ÏlsïÏI-t;hght
th0ùâhtïîhêÿî
over
Ï
ï And each}: specœsms@W
=: ptcul way has—donc
—