266
.THE BlOLOGY OF FÏSHES
:
.»
inuence "of other forCes than the purposes
-'
'
to— be regarded as adaptations. But extreme cases
:
may well be called
for ”example, thesuctorial apparatus“
Ï ÏÏ Î
of the parasitic Hag—shes and Lamprey. Myxine has
_
only a single tooth in the roof of its mouth ; it is not really
=
a tooth in the same s’enseas the teeth of the Shark or. bony ,
Î
‘
sh, being only a horny cone hardened by much use, yet
it is very efcient.
Getting this tooth into its victim,’
,
preferably one already caught on lines or in a net _and
;
unable.to escape; Myxine boresits way into the tissues by
'
,
méans=of its rasping tongue and leaves very little for
'
sherfnan. - Regarding the destructiveness of the Ambrican:
î
'
,
Borer;]ordan and, Evermann write,
“
Large shes of even
are often brought up without esh and
%;
Sthout.Viscera, and they certainly do not swim into, a gill—
'
,
Inste'ad‘ of
the Lamprey—S
‘
have ,a large fu—nnel With a-Ïs‘ucking disc at the end, which"
ÏÏ_
the same purpose. . And they, do not;readily let
-
“the marine Lamprey has been Carried by the Salmdn long
,
distances into fresh water.
One American Lamprey seems
,
to
have acquired» such a masteryof this apparatus that:it
:
,
Dean has describedhôW the males.
:
,
andjfe‘mal‘es
againe of lifting stt>nes,,—piling.tlæŒ
corner, removing
Î
one another,- Whilstr"edæv0ùrig
—,poSsible tha—t : this,-playing
? with astructurel‘ organ
'
Ï'äÿ,
:
.
'5
the €rSh maY hâŸe acquired >Ÿ hashadagooddealtodownh
,_
thedeveloPmentofadaptation—°»
…………1…1b…h…h
;
111mnyshesepecanyqsewhich ;:‘h‘ave few or small
::
teeth,hketheRedMullets,Stu1geon,and Some Of
'
Among theGad01dswe can followits
is quite absei ‘
ï
the
,Pollack and-——Greenæcod)ato a“ little longer
£,
Still—longer in; the“ Lings-,— and:_it—hen- tOi—à varÿingüè} :
£numberupmve
ëRockhngshave{raîhçî‘smaeï eyes than—théiothèféaaïälieäfhe
-*‘î-i
.THE BlOLOGY OF FÏSHES
:
.»
inuence "of other forCes than the purposes
-'
'
to— be regarded as adaptations. But extreme cases
:
may well be called
for ”example, thesuctorial apparatus“
Ï ÏÏ Î
of the parasitic Hag—shes and Lamprey. Myxine has
_
only a single tooth in the roof of its mouth ; it is not really
=
a tooth in the same s’enseas the teeth of the Shark or. bony ,
Î
‘
sh, being only a horny cone hardened by much use, yet
it is very efcient.
Getting this tooth into its victim,’
,
preferably one already caught on lines or in a net _and
;
unable.to escape; Myxine boresits way into the tissues by
'
,
méans=of its rasping tongue and leaves very little for
'
sherfnan. - Regarding the destructiveness of the Ambrican:
î
'
,
Borer;]ordan and, Evermann write,
“
Large shes of even
are often brought up without esh and
%;
Sthout.Viscera, and they certainly do not swim into, a gill—
'
,
Inste'ad‘ of
the Lamprey—S
‘
have ,a large fu—nnel With a-Ïs‘ucking disc at the end, which"
ÏÏ_
the same purpose. . And they, do not;readily let
-
“the marine Lamprey has been Carried by the Salmdn long
,
distances into fresh water.
One American Lamprey seems
,
to
have acquired» such a masteryof this apparatus that:it
:
,
Dean has describedhôW the males.
:
,
andjfe‘mal‘es
againe of lifting stt>nes,,—piling.tlæŒ
corner, removing
Î
one another,- Whilstr"edæv0ùrig
—,poSsible tha—t : this,-playing
? with astructurel‘ organ
'
Ï'äÿ,
:
.
'5
the €rSh maY hâŸe acquired >Ÿ hashadagooddealtodownh
,_
thedeveloPmentofadaptation—°»
…………1…1b…h…h
;
111mnyshesepecanyqsewhich ;:‘h‘ave few or small
::
teeth,hketheRedMullets,Stu1geon,and Some Of
'
Among theGad01dswe can followits
is quite absei ‘
ï
the
,Pollack and-——Greenæcod)ato a“ little longer
£,
Still—longer in; the“ Lings-,— and:_it—hen- tOi—à varÿingüè} :
£numberupmve
ëRockhngshave{raîhçî‘smaeï eyes than—théiothèféaaïälieäfhe
-*‘î-i