their remains from Mesozoic strata is rather remarkable."[1] But the difficulties in the clear conception of this question do not end here. As early as this Carboniferous epoch, these insects appear to have possessed what we naturally consider as a protected or imitative structure, and this view is inconceivable without the antecedent proposition that their enemies then existed, and that the imitative guise was that of the oft-devoured against the would-be-devourer. But it is affirmed that Lizards do not appear before the Permian epoch,[2] birds as certainly not before the Jurassic[3] or perhaps the Triassic formation. "It is quite possible that birds existed during the Triassic period, but at present there is no proof of it."[4] And if these facts were taken as final, then an insuperable difficulty would exist as to the structure of these Phasmidæ being due to a gradually acquired protective character. But the same argument applies to these ancient Lizards as to our Carboniferous Stick-insects. As Huxley remarks, "These Permian Lizards differ astonishingly little from the Lizards which exist at the present day"; and again, "It is perfectly clear that if our palæontological collections are to be taken, even approximately, as an adequate representation of all the forms of animals that have ever lived, and if the record furnished by the known series of beds of stratified rocks covers the whole series of events which constitute the history of life on the globe, such a fact as this directly contravenes the hypothesis of evolution; because this hypothesis postulates that the existence of every form must have been preceded by that of some other form different from it."[5] If we study the records of
- ↑ Scudder, "Syst. Rev. Pres. Knowl. Foss. Ins." (Bull. U.S. Geol. Surv. No. 31, p. 49 (1886)).
- ↑ This seems to be the current statement based on present knowledge; but, as Huxley has observed, analogy seems to be rather in favour of, than against, the supposition that Amphibia and Reptilia, or even higher forms, may have existed, though we have not yet found them in the Devonian epoch ('Collected Essays,' vol. viii. p. 385).
- ↑ The oldest known bird—Archæopteryx—comes from the Solenhofen Limestone in the Upper Jurassic series—a rock which has been especially prolific in the fauna of the Jurassic period (A. Geikie, 'Text-Book of Geology,' 2nd edit. p. 783).
- ↑ O.C. Marsh, 'Sixteenth Ann. Rept. U.S. Geol. Survey,' p. 147 (1896).
- ↑ 'Collected Essays,' vol. iv. p. 85.
