As with these, so with the relics of every succeeding epoch, in which all the types, the genera, and species of every family of the animal kingdom, are represented by organic structures as perfect as those of the present day. We quote the following important cautionary remark by the same author:—“We ought not,” says Professor Pictet, “to be too hasty in assuming the absence of certain more perfect types in the older faunas, merely because we have not yet discovered any remains of them. We hardly know anything of these faunas, except with regard to some of the inhabitants of the sea; and it is well known, that in the present condition of the globe, those animals living on land exhibit the higher forms of structure. Is it not possible that in these first ages of the world, terrestrial animals also existed, more highly organized than their marine cotemporaries, although their remains either have not been preserved, or are still to be discovered? The existence of didelphine mammals in the oolites has been made out by the discovery of a very small number of fragments; and the remains of land animals generally are hardly fossilized, except by sudden deluges and inundations, which are always trifling in their results, compared with the slow but unceasing deposits from the water of the sea. May we not yet expect new discoveries in these ancient strata, revealing to us the existence of primeval animals at present little suspected?” The same mode of reasoning may be extended to the ancient floras, or terrestrial plants of the primeval ages. What a revelation, for instance, is made in the recently discovered coal deposits of Oporto and the Upper Douro, where, along with the orthides, trilobites, and graptolites of the lower silurian rocks, are found vegetable impressions strongly resembling the ferns of the carboniferous age? The Cromarty fossil pine, from the lower old red sandstone, has been already noticed. While these pages have been passing through the press we have to record the discovery of a specimen, nearly two feet in length and half a foot in thickness, from the beds of the middle old red and immediately underlying the yellow sandstone of Dura Den. This fossil is considerably flattened and furred with the scars or markings so characteristic of the decorticated trees belonging to the coal formation. Does not this warrant the expectation of a richer harvest to be yet gleaned in these ancient fields than the marine fuci and algæ that have hitherto been mainly gathered in by the geological sickle?