Joshua Platt

“ Poupart, which led me to examine into the growth of the cowree; and by sawing one of them through the middle, I found a turbinated shell within the outer wall, consisting of six or seven convolutions, but no stages, or periods, of the indented lip appeared in any of the convolutions, as we find in the helmet shell, and several of the buccinæ. I then began to consider how this animal enlarged its dwelling; and was fully convinced, that no more convolutions could be carried on; the indented lips being a full stop to its inward dimensions ”

“ For no testaceous body can be formed without an inhabitant; nor does it appear to me, that any Belemnite was ever formed without an alveolus, or concamerated shell.
The conical cavity and its nucleus are always proportioned to the bulk of the Belemnite, but not to its length: some are four times longer in proportion to the alveolus than others. The apex of the conical cavity, where the alveolus is first formed, in some runs up about half the length of the whole Belemnite ”

“ Besides, were we to consider it in this view, the recent and fossil remains would be found to throw a mutual light upon each other, and the naturalist would not be so often at a loss to class every new fossil acquisition, of which the recent specimen is not to be found, especially whenever the fossil has any thing seemingly æquivocal in its formation, so as on a superficial imspection to render the matter doubtful, whether the body belongs to the animal or vegetable kingdoms, or indeed to either of them. ”

“ In the clay at Shotover [29] near Oxford, they have a curious smooth surface, but are otherwise imperfect: at Stonsfield, in the slate-stone, they are generally crushed [30] : those approaching nearest to perfection, which I have seen, came out of the sand [31] , under the bed of stone at Garsington-pitts near 0xford: the outer part is quite perfect, and the verge of the conical cavity is as thin as paper, but the alveolus is destroyed, except the apex or point. ”

“ But when we bring them to chemical tryal, the objection vanishes; for the bones either come out of the furnace with a black core, or they are reduced to ashes; whereas the Belemnite is changed into a fine calx, after the manner of all testaceous bodies, and is converted into a species of phosphorus [26] . The oisters, having no loco-motion, frequently affix themfelves to other bodies, that they may be better able to stem the tides, and currents, which might otherwise carry them from their proper beds, and places of feeding. ”

“ This attachment to other bodies no way incommodes them, because they increase the dimensions of their shells by adding fresh laminæ inwardly: the first formed laminæ, being, as it were, excluded, lie in the manner of tiles upon the roof of a house, and exhibit the several steps or stages of their growth.
I believe a Belemnite is very rarely found perfect in the fossil state: those in gravel-beds [27] have suffered very much by being rubbed against stones, &c. ”

“ We must therefore have recourse to the different steps or periods of their life and growth, as they are marked out by the indented lips or foldings of the shell; untill they arrive at their full size; when they begin to fortify themselves, by bulwarks and strong holds, against the injuries and incidents, which attend old age. This is most conspicuous in the cowree, or concha Veneris of Lister, book iv. ”

“ Figure X. represents the Belemnite split up the middle, with the siphunculus in the front: a, b exhibit the first formed cell, or seat of the animal ab ovo. As the animal grows larger, it forms a second cell or chamber b to c, at the same time covers the first cell, by forming theappendage or guard c, i, which is the first stage of the Belemnite. In forming the third cell c, d, fresh laminæ or coverings are carried on from d, to k; and so of the rest, e, f, g, h; or l, m, n, o. When we have duly considered the manner, in which the shell is thus formed ”