One of the species examined by the illustrious botanist above mentioned, was thought to resemble a Pteris, an other a Dicksonia, while others were more like to Poly podium, Adiantum, and Osmunda ; and in all these cases, the individuals which they most resembled were the in habitants of hot climates. More ancient naturalists, such as Woodward, Plukenet, and others, having previously settled with themselves that such fossil plants were the same as living species, were used to speak with more con fidence, and have thus given names without any hesitation, and which, it is now very evident, were unfounded. Thus they mention Osmunda regalis, Adiantum viride, Poly podium filix rims, Polypodium filix fcemina, Asplenium ruta muraria, Asplenium scolopendrum, and other ferns, together with Typha latifolia, Pinus abies, some Equiseta, and the Myriophyllum vulgatum. But even these bota nists acknowledge that eighty-eight out of 110 bore very little resemblance to any plants which they knew, and that the remainder were totally dissimilar.
Volckman, a German naturalist, imagined that he had found the Galiom montanum ; and Da Costa thought that certain specimens which he found in England, and also on the Contincut, were Euphorbix, Cacti, pines and reeds. It is among the round or flattened squamous, or figured trunks, that the Cacti and Euphorbix have been sought, while some of these also have been compared to palms, and others to firs. Stems of some kind of reed are recognised by their size, their knots, and their linear leaves ; but we are as far off as ever from assigning either the species or the genera. Scheuchzer, indeed, describes and figures what he considered the Arundo phragmites, as did Volck man the sugar cane ; and the Acorns calamus and Bamboo have been mentioned by others.
But these are effects of the imagination ; resemblances, not identities; while many seem to have no living analo gies, at least among plants yet known. Such is a cylin drical and striated stem very often found in the sandstone of the English coal series, specimens of which have been procured, reaching to fourteen feet in length. Such a specimen was discovered, which terminated in a point at one end, and to a knot or root at the other, while the mid dle was nine inches in circumference. Others of these cylindrical stems are found covered with tubercles ; and one kind, very common, is a long compressed cylinder, thickly beset, in alternate or quincunx order, by regular depressions, in each of which there is a small tubercle, not rising beyond the general surface. Besides this, the same fossil often contains a rough imbricated surface or tube within, running through its whole length : and sometimes there is also an external furrow, bounded by one sharp ridge, running in the same direction.
Another remarkable vegetahle fossil, a figure of which has been given by Mr. Parkinson in his Organic Remains, is an oblong cylindrical body, imbricated with scales on the surface something in the manner of a fir cone; a kind of tube proceeding inwards from each, at right angles, to the surface of the cylinder, till they all meet a hollow that runs through the centre. This body has probably been
the strobilus or cone of some unknown fir.
Besides the leaves of ferns already mentioned, some naturalists have imagined that they have found the com pound leaves which are so common among the umbelli ferous plants. This is very possible ; but in all the speci mens which we have examined, we have seen none that might not have been a fern. The leaf of our own Pteris crisps might, in a compressed state, be easily mistaken for some of the highly compounded leaves of this tribe. Leaves of woody trees or shrubs, of different forms, have also been observed, but they are not so common as many other objects of this nature. To determine to what trees they may have belonged, is equally impossible; but, among the resemblances, may be traced some to the Spirxa, the elm, the willow, and others ; while among herbaceous plants, there are resemblances, as we before remarked, to the Rubiacex, (galium, for example,) as well as to Hippuris, Equisetum, and other aquatic or semi aquatic plants.
The ancient naturalists had sometimes imagined that they had discovered flowers in a fossil state ; but all the specimens hitherto produced have proved to be either groups of verticillated leaves, or sections of some of the lithophytes. From the perishable nature of these, it is in deed scarcely to be expected that they should be found in such circumstances. Seed vessels, or fruits of different kinds, being of a much more durable nature, have, how ever, occurred ; hut even in this case the ancient mineralo gists have fancied the presence of such objects among flints, claystones, and other mere mineral substances, where some vague resemblances of form have existed be tween these two very distinct classes of objects. Thus there have been described and figured the olive, apple, plumb, almond, cherry, pear, nutmeg, walnut, and others; most of which have been such accidents as we just men tioned, while others have proved to be zoophytes. The fruits found in. the Sheppey clay, which we already no ticed, are not included in this remark, as these admit of no doubt ; and yet, even in this case, some pyritical concre tions, which have no claim whatever to a vegetable origin, have been enumerated among these. Thus it has been imagined that there had been discovered the fruits or ,seeds of the American soap tree, of the sand box tree, the coffee, and many other foreign seeds, together with acorns, and other domestic seeds, fruits, or seed vcssels. It is better ascertained that there have been resemblances dis covered to some leguminous seeds, the fruits of some palms, of the chesnut, of a cocoa, &c. but where there is so much of conjecture, and so little that is satisfactory, we need not prolong these remarks.