For myself, I will at once say that I have no doubt it was animal; but not an animal of a very high order. The specimens which I now possess, and which are all of them chosen, some of them _rare_, I should assign to such creatures as the “zoophytes” or “polyps,” both radiated and globular. And I know of nothing, among many hundreds of specimens gathered from a dozen different beaches, which presents the evidence of having belonged to vegetable organization, with the exception of sundry varieties of petrified wood, which speak for themselves, and could not be mistaken by anybody. I will now state two or three reasons, which to my own mind are conclusive, for the above decision. In the first place, then, the structures here perpetuated in stone are of great delicacy, and they have been immersed in ancient seas, as is testified by the localities in which they are obtained. Now vegetable structure as fine as this, if immersed long enough for any such change to come in question, must have utterly perished by maceration, and then the petrifaction could not have taken place. I know that part of the stem (and I think fruit) of one species of “conifer” has been found in the Isle of Wight in the condition of a fossil; but this belonged to a hardy class of plants, and the lobes or plates which composed its bark and husk are themselves highly siliceous, to say nothing of the presence of iron in the rind of most of these stems. So that the process would be a long one, and the fibrous material of the tree would stand it well. But in these pebbles some of the threads or tubes run from the size of small twine to that of the rays in a spider’s web; and no vegetable substance with which I am acquainted, excepting the filaments of “asbestos” (which is a vegetating _mineral_) in rock-crystal, could abide and retain its form, so as to allow of the changes by infiltration or otherwise which have passed upon the original structure. If it be said in reply to this, that we have the exquisitely delicate “dendritic” markings, as of leaves and filaments of shrubs or sea-weed, in the heart of the white chalcedony “mocha-stones” from the East, the answer is evident: these are not _really_ vegetable traces, but only _resemble_ such in their configuration and colours. They are simply shoots and ramifications of a metal,—as iron or manganese. Those in the “weed-agate” of India, which exactly resemble sprays of fine sea-weed, are produced by “delessite.”