well-marked mollusc--the large tortoise-shell helix (_helix aspersa_), very abundant in this neighbourhood--I had never seen in the north at all. I formed, too, my first acquaintance in this woody, bush-skirted walk, with the hedgehog in its wild state--an animal which does not occur to the north of the Moray Firth. I saw, besides, though the summer was of but the average warmth, the oak ripening its acorns--a rare occurrence among the Cromarty woods, where, in at least nine out of every ten seasons, the fruit merely forms and then drops off. But my researches this season lay rather among fossils than among recent plants and animals. I was now for the first time located on the Carboniferous System: the stone at which I wrought was intercalated among the working coal-seams, and abounded in well-marked impressions of the more robust vegetables of the period--stigmaria, sigillaria, calamites, and lepidodendra; and as they greatly excited my curiosity I spent many an evening hour in the quarry in which they occurred, in tracing their forms in the rock; or, extending my walks to the neighbouring coal pits, I laid open with my hammer, in quest of organisms, the blocks of shale or stratified clay raised from beneath by the miner. There existed at the time none of those popular digests of geological science which are now so common; and so I had to grope my way without guide or assistant, and wholly unfurnished with a vocabulary. At length, however, by dint of patient labour, I came to form not very erroneous, though of course inadequate, conceptions of the ancient Coal Measure Flora: it was impossible to doubt that its numerous ferns were really such; and though I at first failed to trace the supposed analogies of its lepidodendra and calamites, it was at least evident that they were the bole-like stems of great plants, that had stood erect like trees. A certain amount of fact, too, once acquired, enabled me to assimilate to the mass little snatches of information, derived from chance paragraphs and occasional articles in magazines and reviews, that, save for my previous acquaintance with the organisms to which they referred, would have told me nothing. And so the vegetation of the Coal Measures began gradually to form within my mind's eye, where all had been blank before, as I had seen the spires and columns of Edinburgh forming amid the fog, on the morning of my arrival.