He then shows how in some localities there are now forming coral deposits, in some places chalk, and in others beds of Molluscs; while in still other places entirely different forms of life are existing. In fact, each zone or depth of the ocean has its particular type of life, just as successive altitudes do on the sides of a mountain; and it is a dogmatic and arbitrary assumption to say that such conditions have not existed in the past. "On our own coasts, the marine remains found a few miles from shore, in banks where fish congregate, are different from those found close to the shore, where only littoral species flourish. A large proportion of aquatic creatures have structures that do not admit of fossilization; while of the rest, the great majority are destroyed, when dead, by the various kinds of scavengers that creep among the rocks and weeds. So that no one deposit near our shores can contain anything like a true representation of the fauna of the surrounding sea; much less of the co-existing faunas of other seas in the same latitude; and still less of the faunas of seas in distant latitudes. Were it not that the assertion seems needful, it would be almost absurd to say that the organic remains now being buried in the Dogger Bank can tell us next to nothing about the fish, crustaceans, mollusks, and corals that are now being buried in the Bay of Bengal." This author evidently found it difficult to keep within the bounds of parliamentary language when speaking of the absurd and vicious reasoning at the very basis of the whole current geological theory; for, unlike the other physical sciences, the great leading ideas of geology are not generalisations framed from the whole series or group of observed facts, but are really abstract statements supposed to be reasonable in themselves, or at the most =very hasty conclusions based on wholly insufficient data=, like that of Werner in his "narrow district of Germany." Sir Henry Howorth[2] has well expressed the urgent need that there is of a complete reconstruction of geological theory: "It is a singular and a notable fact, that while most other branches of science have emancipated themselves from the trammels of metaphysical reasoning, the science of geology still remains imprisoned in _a priori_ theories." But Huxley[3] also has left us some remarks along the same line which are almost equally helpful in showing the essential absurdity of the assumption that when one type of life was living and being buried in one locality another and very diverse type could not have been doing the same things in other distant localities. This is how he expresses it: "All competent authorities will probably assent to the proposition that physical geology does not enable us in any way to reply to this question--Were the British Cretaceous rocks deposited at the same time as those of India, or were they a million of years younger, or a million of years older?"