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VARIATÏON* ÀND fDÏFFÈRENTÏÀTÏONQ 199
‘
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Muîa‘tions do not break through »àny law Of
;
they make things” diîèult ”for
natural »Selee‘tioiStÇ’ …
_
Organs like the
and operi air—bladder duct,wluchareûf :
'
pr0ven utility,
'ôr} dîsappœ;
à very
large
comefromgusîîhese
»
two mutations—L‘
In short,wecanundersîemdmU—ÎÊIÜOns
and recogniSe' the = imp0rfañt ïpartthey
Lg '
differentiation of $hes fârÏbje‘îte‘r :if weleàvena‘turalselecüen
Out ofcmsidæà0n;
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*
ÿ
_
.
Î}'f
;:çî_i
The
agreat
deàl of,, light
,
andhab1tso£shesThe
;éommnieatiô;
? forexampîe ._
'
'broughtW1thlt
t0‘règul'a'œ the
î
externalpressure
shes were 'Oblig‘ed; ”either
_
.:
remain at & denîte level, at the Surface like many
Plectogaths or near the bottom like the Blennies and many
Or to develop their swimming powers like
‘bf0ids, or to acquire‘a‘ new regulating apparatus
'ï
likethe Sciænoids, Gadoîds, and others
.
understand how dierehëes ms‘cx‘uCîure
&
acîapœd
-
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yet So far' from
comprlseperhapsîhe
>
. majority of shes‘ at“ thë‘prcsent
have ,S,urVived and 1èà tofurtherderemætmnCannet
on»ändthelrablhîytocoordmatethelïstmCïuœsad
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