have been hollowed out to their shells and then filled in. Whether these fruits and other vegetable remains in the chalk be so rare as has been thought, I somewhat doubt. I have myself collected fragments of fossils from the lower chalk of Dover and of Maidstone, which I believe, since I have seen these specimens, to have been fruits like them—and some few of these I think are still in the Folkestone collection—but in all cases the specimens seem to have suffered much decomposition from long-continued immersion before they were completely imbedded.
Here then, at the very outset, we are met with a difficulty which must be surmounted before we can compare with any usefulness these relics of the arborescent vegetation of the far-distant Cretaceous age with the fruits of any living class of trees. There are some in the botanical collection in Kew Gardens which present many points of similarity, but we should by no means be inclined to say of identity. The greatest mischief to fossil botany has arisen from the fact that many, if not most of our fossil species, have been named and described by men who were not botanists; and as so little is known of the vegetable remains preserved in the English chalk, we refrain from giving, and should hesitate long before we assigned, botanical characters to any new form from that formation, especially when so vaguely preserved as those before us.
We would however suggest that the film-like character of the ochreous envelopes of these fossils may be thus explained:—Supposing the fruits to have been solid nuts contained in a husk like the nipadites,—and in the cases of the British Museum there are fine specimens of nipadites from the middle eocene of Brussels, well riddled with teredines; the same is well known to be the case with the nipadites and other nut-like fruits of the London clay,—while the nuts were in the earliest stage of decay, a film of sulphuret of iron was deposited in the empty interspace between the nut and its outer husk, forming thus, when solidified, a thin metallic paper-like pellicle or case, having on its interior surface the impression of the exterior surface of the kernel, and on its exterior surface that of the interior of the husk. The fruit and husk might both then wholly decay away, and leave this metallic shell to be imbedded and filled in by the natural deposition of the cretaceous mud. Thus it will be desirable in searching for further specimens to look carefully for, and to preserve any fragments of real wood or black charcoal, however small, which may be attached to the inside or outside of the ochreous film, as in these fragments we might get some traces of structure to aid us.
