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(1

This will come under Geograph. Distrib

Though time is most important element as giving many individuals, perhaps many individuals at same time very important, as giving scope of selection, yet to arrive at the present complication in almost every great branch of organic life, the whole land & whole ocean has been requisite, so as innumerable species may have been formed & become extinct, the best adapted & most divergent being preserved, so as to most fully to cover the earth & fill the ocean. As this has been so, we can understand that any confined & peculiar habitat, although capable of supporting many individuals, & though capable according to all analogy of supporting still more if such existing with very divergent structures & habits, though of most ancient date, yet according to the above principles, we could not expect so much diversity of organic beings, for similar scope has not been here given as over the land & ocean to selection. This seems to me a legitimate conclusion. Hence we can understand why the lakes, all those whether of temperate for or tropical regions, are small compared to the coast-seas though abounding with individual animals, should not, as has often been remarked with surprise, shd not in same area, contain nearly so many forms, as an equal

[195]

(2

Area of tideless sea - As the lake area is bigger so is diversity as in N. America. Thus we can understand the same remark in regard to Arctic Ocean, which compared to temperate & tropical ocean is such, & which in eocene period, must have been extremely small if it existed, & when Melville Isld was covered with a Carboniferous Flora cd hardly have existed. Thus Baltic which must has been peopled since Glacial, compared with Caspian, which has endured since Miocene. So with brine lakes of Utah &c.

[in margin:] (Back)

 

It may be too hypothetical, but the very same cause which prevent complication wd tend to leave the inhabitants of such peculiar habitats in lower state of complication. They wd be like fossil, pr wd be allied to those intermedial form, which we must believe to be parent of present orders & Familia. Now considering the fewness of F.W. forms the proportion of Being in this condition is surprising but it is very easy to deceive myself. Ganoid Fish - Lepidosiren (Proteus?) - Ornithorhynchus? new Echidna. In plants generally lowly organised & I think intermediate & obscure affinity look through Lindley. Are not Crocodiles most related to Enaliosaurians of all living Reptiles. [illeg] exception - Trilobite & Brachiopods. Count?

On same principle of less quick [illeg] & less extinction we can understand Heer statement of relation to Madeira plant to fossils of Europe.

(over

[2v]

(A Mem.)

Coleus insects as diverse as plants on coral islets. We see beginning of specification.

Hence we may say F.W. productions are living fossils.

N.B:  Fr water lakes & rivers so small area, perhaps too much disjoined.

In considering plants we shd take aquatic Families, for these must be ancient - lower simple species as Subularia amongst the Cruciferæ may have become recently adapted.

I do not think my remark holds to insects, which are terrestrial productions changed into aquatic.

N.B

I fear the contrast of marine plants, which are lower than Land, knock all this pretty theory on Head.

Turbulence of sea may be cause, but it will too much complicate the argument

Then again so many water plants are degraded Land Plants

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18

(Chapt 11 on Geograph Distri)

My proposition is that where close representative species occur, there has been channel of communication, by which species have entered & became modified, - as is found from presence of identical species - at least in eyes of those who believe in single creation – at channel having been possible under altered climate or with land at different levels - or as inferred by simple geographical position; for under whatever contingency it is generally more probable that form derived from nearest lands - opposed to last proposition Kerguellen Land, already discussed. Vaccinium on mountains of Sandwich Isd.

The Representative species of New Zealand — yet accords with geographical position & some species in common though it cannot be accounted how these species came to be in common.

Sum up the cases of representative species in last Chapter