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It is of importance to know that according to palaeontological investigation, empiric systematizing and phylogenetic classification do not always coincide, as, for instance, in the case of the ammonites. Acording to palaeontological investigation the great systematic categories are only grades of organization.
Some years ago one of your Secretaries pointed out another kind of positive palaeontological evidence tending towards the same conclusion afforded by the existence of what he termed "persistent types" of vegetable and of animal life. He stated, on the authority of Dr.
Darwin relies upon indirect proofs, the bearing of which is real and incontestable"; who concedes that "his theory accords very well with the great facts of comparative anatomy and zoölogy, comes in admirably to explain unity of composition of organisms, also to explain rudimentary and representative organs, and the natural series of genera and species, equally corresponds with many palaeontological data, agrees well with the specific resemblances which exist between two successive faunas, with the parallelism which is sometimes observed between the series of palaeontological succession and of embryonal development," etc.; and finally, although he does not accept the theory in these results, he allows that "it appears to offer the best means of explaining the manner in which organized beings were produced in epochs anterior to our own."
Not only, therefore, has the botanist afforded the geologist much palaeontological assistance in identifying distinct tertiary formations in distant places by his power of accurately discriminating the forms, veining, and microscopic structure of leaves or wood, but, independently of that exact knowledge derivable from the organs of fructification, we are indebted to him for one of the most novel, unexpected results of modern scientific inquiry.
Scarcely any palaeontological discovery is more striking than the fact that the forms of life change almost simultaneously throughout the world.
Proofs that distinct Species of Animals and Plants have lived at successive Periods. Distinct Provinces of indigenous Species. Great Extent of single Provinces. Similar Laws prevailed at successive Geological Periods. Relative Importance of mineral and palaeontological Characters. Test of Age by included Fragments. Frequent Absence of Strata of intervening Periods.
Seventy-nine species of fossil shells, in a tolerably recognisable condition, from the coast of Chile and Peru, are described in this volume, and in the Palaeontological part of M. d'Orbigny's "Voyage": if we put on one side the twenty species exclusively found at Concepcion and Chiloe, fifty-nine species from Navidad and the other specified localities remain.
He observed that the oldest fishes present many characters which recall the embryonic conditions of existing fishes; and that, not only among fishes, but in several groups of the invertebrata which have a long palaeontological history, the latest forms are more modified, more specialised, than the earlier.
Considering the parallelism which prevails throughout organic nature between palaeontological and embryonic development, it is therefore improbable that the oldest Insects should have possessed fewer segments than some of their descendants.
Among the fossil specimens already found in California, but which our trustworthy palaeontological botanist has not yet had time to examine, we may expect to find evidence of the early arrival of these two redwoods upon the ground which they now, after much vicissitude, scantily occupy.
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