There is, further, no real dispute that the Saurians led up to the Aves, and that the third group (of mammals) follows all the members of the second group. The earliest known mammal (_microlestes_) is an isolated forerunner of not very certain location, the real bulk of the mammalian orders beginning in the Eocene. Seeing, too, how very closely one Creative command is recorded to have followed on the other, it is not in any way against the narrative that some land forms of crustaceans and insects (and possibly others) began to appear at an early stage, when the vegetable and water-animal forms had only progressed as far as the Silurian and Devonian ages. Nor should we wonder if mammalian forms had occurred earlier. I mention this because of the evident gap in the geologic record between the Cretaceous and the Eocene, and because in the article of December, 1885 (and elsewhere), Professor Huxley has used language which suggests that mammals may have existed of which the rocks give no sign. E.g. (p. 855): "The organization of the bat, bird, or pterodactyle, presupposes that of a terrestrial quadruped ... and is intelligible only as an extreme modification of the organization of a terrestrial _mammal or_ reptile." The italics are of course mine. And again (p. 855), "I am not aware that any competent judge would hesitate to admit that the organization of these animals (whales, dugongs, &c.) shows the most obvious signs of their descent from terrestrial quadrupeds." I do not quote these words of so great a master as presuming to question them (even if, as a scientific verdict, I had any motive for so doing), but merely to point out as a matter of plain and fair reasoning, that if a Divine Creator had designed certain forms to be gradually attained by the processes of Evolution, it would not be necessary that any actually realized form or tangible creature should have existed as ancestors. Logically, the necessity is _either_ that certain animals should have actually existed whose descendants gradually lost or gained certain features and functions till the forms we are speaking of resulted, _or_ that certain patterns or designs should have been created according to which development proceeded by regular laws till the forms in question resulted. A few words as to the terms used in describing the contents of each group, may be added. It is obvious that the terms are intended to be exhaustive of certain main groups which are described sufficiently, without being cast in a form which would have been incompatible with the use (at the time) of a human agent as the medium of the recorded Revelation. (1) "Vegetation" (of an indefinite character, but not bearing seed), plants bearing seed, trees bearing fruit with the seed in it--certainly exhaust the entire range of plant-life.