_
THE ”GENEALOGY OF FISHES
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221
According to Wegeer, the land—masses have not greatly
altered, except for the rolling together of the mountains,
since the beginning of the, geological epochs. Thus we nd
the oldest deposits still near the surface and the mar-ine
deposits, With a few doubtful- exceptions, haVe come fr0m
marginal oodings of “the - continental shelVes. The
principal changes, so far as the distribution-of animals and
;
plants is_concerned, have arisen from…theslidig away…of
one continent from another.
:
_
7
-
“.
The following chart (from Wegener)shows the dispositi0n of the landrand water during the
of…the
i
—
…
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.
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,
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«;
-
_
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/°‘
.
_
«“
j"
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…,
,
_
‘
‘
ïFm'. '53'î—BositiÔn- bf the c‘ontinen'ts during thé carbonifero'us
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period.
:
-
;_.
?;
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{
Carboniferous period, thus at a_tim€ when
»
already numerous in the world. The position of the-water
.
on the land is,
merely suggested and is not meant
'
to-—be representative of the actual conditions, which must .
.indeed have been quite different, to judge from the distribu_
tion of shes.
A second.difculty arises from the view that
the deepeSt parts in the—oceans represent the earliest.brëal$
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i‘m-the lithospher'e. ‘» In general, thisis_ probably c0rtect;
7
-thePacic, we believe,
this again older than
part _of‘ithç
lieS.;in:thÇ—;_WŒÎÇ5
>
:
as“
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'—
a
represented:in;.thÇeÎÇhar‘tsgwithï—thç lands Stillginÿcoîàct tO"athe