z7o_”
THE BIOLQGYOF "FISHES
—
and is provided witha.transversely'plaited disc betweenthe‘ -_
'
But'—'apart from these examples, freshwatef
shes_manage to=keep their places without sucking-discs; —
‘The origin of these discs müst be referred, therefore,
simply to the habit of resting on the bott0m, and the_necesSäry condition for their development appears to be the suit—
able position of either the ventral or pectoral ns. 'The…
{
sucker is only developed, on the anterior half of the belly,
that
the ventfal ns are anterior. The
of
stickers in the freshwater shes is— thus—accounte‘d for by
the fact that in most of them the ventrals are
J
'
_
,
,
_'In many marine'»;forms, forreXampk—the Anglè‘rs (Pedi-l
‘
and the,—,‘Rocldings, the bellÿis
_
_
andoffandpulpyamfthesh1iteral—ly=clung—to the bettom.
,
Butam0redemteswkermf@“medbytheventrals1nthe
'
7
'
‘ca3e of
Which live in
.
,
no current, the sUcker is but feebly developed "and13
_
perhaps moreÇa tactile organ than a sucker.
"
,Ajstill‘greater development of this apparatus is seen in
the _Cling—Jshes (Gobiesocidæ). Here the ventrals are
stillfurther forwardand more to theside ; between them
-_
,
,lie the expanded ends of the ClayicleS and behind are-the
îlarge post—clavicles,… The skin covering these
,
'
—
ä'dhŒÎYÊ’-fifïWhÊ—ëthËÊ-Sh
,
se1esdownhoweverthesucuon1smcreasedbyashght
lÏ- fïÏ° Withdrawaî0fthecentralpartofthdlscand
'
_
ma backetofseawaterandallowedtox itself on the
__
'
: ,
? bottomthenthebucketwaterandsh have .bæ —lifted; ; ;
srmplybypullmgupthesh,sormlyd1dit»cling..—J
*
Ï
;
L__.5.“Thepectorfalîiàndventrali'rays in—…sbnîe;shes gré—also
used just'like theibarbelsfonthe'
and thi‘Oät as’tàctile
-
'
:
offood;
'
'
arose_
Ïj_so_me
using f the raÿsÏas
;
‘$@täP@ntäfè@n-1Stiltsa —:::‘In «therGumards
'
"