higher than either _Lepidodendra_ or ferns. [Illustration: Fig. 56. FERN? OF THE LOWER OLD RED SANDSTONE. (Natural size.)] [Illustration: Fig. 57. LIGNITE OF THE LOWER OLD RED SANDSTONE. (One third nat. size, linear.)] In my little work on the Old Red Sandstone, I have referred to an apparent lignite of the Lower Old Red of Cromarty, which presented, when viewed by the microscope, marks of the internal fibre. The surface, when under the glass, resembled, I said, a bundle of horse-hairs lying stretched in parallel lines: and in this specimen alone, it was added, had I found aught in the Lower Old Red Sandstone approaching to proof of the existence of dry land. About four years ago I had this lignite put stringently to the question by Mr. Sanderson, and deeply interesting was the result. I must first mention, however, that there cannot rest the shadow of a doubt regarding the place of the organism in the geologic scale. It is unequivocally a fossil of the Lower Old Red Sandstone. I found it partially embedded, with many other nodules half-disinterred by the sea, in an ichthyolitic deposit, a few hundred yards to the east of the town of Cromarty, which occurs more than four hundred feet over the Great Conglomerate base of the system. A nodule that lay immediately beside it contained a well-preserved specimen of the _Coccosteus Decipiens_; and in the nodule in which the lignite itself is contained, (fig. 57,) the practised eye may detect a scattered group of scales of _Diplacanthus_, a scarce less characteristic organism of the lower formation. And what, asks the reader, is the character of this very ancient vegetable,—the most ancient, by three whole formations, that has presented its internal structure to the microscope? Is it as low in the scale of development as in the geological scale? Does this venerable Adam of the forest appear, like the Adam of the infidel, as a squalid, ill-formed savage, with a rugged shaggy nature, which it would require the suggestive necessities of many ages painfully to lick into civilization? Or does it appear rather like the Adam of the poet and the theologian, independent, in its instantaneously-derived perfection, of all after development? “Adam, the goodliest man of men since born His sons.” Is its tissue vascular or cellular, or, like that of some of the cryptogamia, intermediate? Or what, in fine, is the nature and bearing of its mute but emphatic testimony, on that doctrine of progressive development of late so strangely resuscitated?