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of a few leaves only in distant parts of the stem. The most useful character to be thus derived, is when the branches regularly bifurcate, for this kind of ramifaction is a strong symptom of cryptogamic plant, especially if accompanied by an imbricated foliage.

In Leaves, we can rarely recognise, in a fossil state, more than their mode of venation, division, arrangement, and outline, to which are sometimes added their texture and surface. All these are of importance, but in unequal degrees. Of the highest value is the evidence afforded by the distribution of the veins, taken together with the mode of division of a leaf; if the veins are all parallel, unbranched, or only connected by little transverse bars, and the leaves undivided, the plant was probably Monocotyledonous; and if the veins of such a leaf, instead of running side by side from the base to the apex, diverge from the midrib, and lose themselves in the margin, forming a close series of double curves, the plant was certainly analogous to what are now called Scitamineæ, Marantaceæ, and Musacea; but, supposing that the parallel arrangement of simple veins is combined with a pinnated foliage, then the plant would probably have belonged to Cycadeæ, that curious tribe that stands on the very limits of Monocotyledons and Dicotyledons, and of flowering and flowerless plants. By such characters as these however, there is no means of distinguishing certain palms, if in a fossil state, from Cycadeæ.

If veins are all of equal thickness, and dichotomous, we have an indication of the Fern tribe, which is seldom deceptive. Nevertheless, it must be remembered that the flabelliform leaves, both of Monocotyledons and Dicotyledons, have occasionally this kind of variation. Even if the veins are not dichotomous, if they are all of nearly equal thickness and very fine, or divided in a very simple manner, it is probable that they indicate the Fern tribe, whether simple, as in the fossil genus Taeniopteris, or reticulated, as in the modern genus Meniscium. If veins are of obviously unequal thickness, and so branched as to resemble the meshes of a net, we have a sign of Dicotyledonous structure that seldom misleads us.

Finally, if no veins at all are to be found, an opinion must be formed, not from their absence but from other circumstances.

If the leaves are small, their absence may be due to incomplete development; but if the leaves are large and irregularly divided, we may have an indication of some kind of marine plant. When leaves are small and are densely imbricated, they are generally considered by fossil botanists to belong to either Lycopodiaceæ, or Coniferæ ; and there is so little to distinguish those families in a fossil state, that there is scarcely any means of demonstrating to which such genera as Lycopodites, Lepidodendron, Juniperites, Taxites, and the like actually belong.

It would be easy to extend these observations much further, but to dwell at length upon this branch of the subject, would carry us far beyond our present limits. We will, therefore, bring our remarks to a conclusion, by calling attention to some of those points, to the elucidation of which, it is most to be wished, that geologists, who have opportunities of collecting fossil plants, would apply themselves.

In the first place, evidence is wanted as to plants to which the cones called Lepidostrobi, the leaves called Lepidophylla, and the fruit named Cardiocarpa, respectively appertain. Are they all portions of species of the same genus, or, as seems more probable, is not Cardiocarpon a part of a plant of a totally different affinity? Secondly, what were the leaves of Sigillaria and of Stigmaria? Of the latter, something is known; but the leaves are always so crushed, that no notion can be formed of their exact nature. Mr Steinhauer says he has traced them to the length of 20 feet! In the third place, to determine the leaves of any of the fossil stems that at present are only in the latter state, such as Sternbergia, Bucklandia, Cycadeoidea, Caulopteris, Exogenites and Endogenites, would be to supply a great desideratum. Again, what was the real nature of the stem of Calamites? Was it an annual shoot, proceeding from a perennial horizontal rhizoma, like that of Juncus, &c.? Had it any leaves, and if so, were they of the nature of those figured in our work, as probably belonging to Calamnites nodosus, but considered by Sternberg and Brongniart a distinct genus, which they call Volkmannia? Another very interesting object of inquiry is into the anatomical structure of Lepidodendron, for the sake of settling whether that extensive fossil genus belonged to Coniferæ or to Lycopodiacea, or to neither. We know nothing of the leaves belonging to the fos

sil fruits called Anomocarpon Musocarpon, &c., or of the fruit of Cycadeoidea, Annularia, Asterophylites and many others.. Now these are difficulties that probably may be removed with diligent research among the beds in which such fossils occur; and which, if removed, would contribute much more to fixing the science upon a solid basis, than the discovery of species not before described.-Lindley and Hutton's Fossil Flora of Great Britain.

On the Vitality of Toads. By the Rev. EDWARD STANLEY, F. L. S., F. G. S., &c. Communicated by the Author.

SIR,

IN No. 25 of your valuable Journal, page 26, you have inserted an interesting paper on the vitality of toads by Professor Buckland. If other experiments, partly similar, attended with similar results, are worthy of recording, you may insert the following.

On the 22d June 1830, I placed three toads, No. 1, weighing 6 drachms; No. 2, weighing 17 drachms; No. 3, weighing 314 drachms, in separate flower-pots, covering the surface with a tile, as well as the hole at the bottom. They were then buried about four feet deep in garden soil, and dug up on the 21st March 1831, all dead. It appeared, however, from the state of their remains, that they had died at different times, the body of one being in nearly a perfect state, whereas of another nothing remained but the bones. Conceiving that the damp state of the soil might have affected them, I placed a 4th in a wide mouthed bottle, corked down, in a dry place, inserted a quill through the cork for the admission of air, and a 5th in a similar bottle, well corked, entirely excluding air, which died before I was aware of it, in 48 hours*; proving very decidedly that air is as essential to their existence as to any other class of living animals. No. 4. continued in apparently good health for about a fortnight: it then, however, began to shew signs of weakness,

* It is scarcely necessary to add, that the air in the bottle was totally unfitted for respiration or combustion; a lighted taper plunged into it was immediately extinguished.

and its eyes became dim, in fact, it appeared so nearly exhausted and dying, that I released it from its confinement, and placed it under a flower-pot on moist garden earth, where it could meet with worms and small insects, and enjoy a sufficiency of air. The consequence was, that in the course of a day or two it had completely recovered its natural colour, brilliancy of eye, and full motion of its limbs; and, when finally released, I had the pleasure of seeing it crawl off under every symptom of entire convalescence. One fact I remarked worthy of notice. I have mentioned that Nos. 4 and 5 were placed in bottles in a dry situation. In consequence probably of this, at the end of about 12 hours I observed them to be in a state of violent perspiration as if every pore was exuding moisture, to such a degree, indeed, that the sides of the glass were covered with a strong dew, which accumulated till it formed drops, collecting at the bottom to the amount of about one-fourth of a teaspoonful. Of the precise nature of this liquid, I am ignorant, but it probably contained a portion of some powerful acid, as in a very short time I observed the ink to disappear from the small labels I had enclosed in the bottles, containing the weights of the toads and dates of their confinement. It is clear from these several experiments, that the commonly received belief that these reptiles can exist in blocks of stone and stems of solid wood, is perfectly false; notwithstanding the almost numberless instances on record, apparently well attested, of their vitality under the joint additional singularity of exclusion of air and privation of food. My experiments are, indeed, more to the point of their inability to exist for any length of time unless amply supplied with air and food of their own selection, than Dr Buckland's; for I should observe, that although in the instance of No. 5, absolute exclusion of air, exclusion of food is also implied, in the cases No. 1, 2, 3, both food and air were both more or less amply supplied, for, in the flower-pots I not only found several small scolopendra, but quantities of more minute insects, consisting chiefly of the Podura fimetaria. Now, it is evident, that to that depth, air must have penetrated, or the insects themselves could not have existed; and that it must have been to a degree quite sufficient for animal life, is equally certain from these insects having descended so far from choice. There is still, however, considerable mystery in the history of

these creatures remaining to be cleared up, and so much conflicting evidence, that I cannot bring my mind to any very positive conclusions *. I certainly have never been fortunate enough to meet with one of the many instances of toads said to have been found hermetically immured in wood or stone, where they must have existed for several years at least; but I have met with them in situations, such as bottoms of shafts, caverns, cellars and crevices, where I could not easily account for a due supply of their known usual food, and, in fact, I selected the imprisonment under flower-pots, as the nearest mode of combining their natural habits with the supposed theory of existence under absolute exclusion. That No. 5, placed in the bottle, died from exclusion of air I think there can be no doubt; and that No. 4, though supplied with air, would have died in another 24 hours, is most probable; but I think it not impossible but that some other causes might have operated, for whenever I observed them, I could not perceive the slightest appearance of uneasiness or sense of restraint; they appeared exactly according to their usual habits, in a sort of dull dormant quiescent state, just as when found in some secluded chink in rocks or under stones, when the only predominant feeling appear to be dissatisfaction at any interruption to their sluggish life, accompanied by an unnatural excitement (I will not call it activity) of their limbs, occasioned by fear, and anxiety to make them retreat with all speed to some similar abode under some other, "cold stone," wherein again to resume their “iron sleep." In a word, the awkward dull movements and lethargic eye of a disturbed toad, seem to express the very sentiments of the Scandinavian prophetess to Odin :

"Now my weary eyes I close,

Leave me, leave me, to repose."

* As the experiments of Herissant in 1777, and Dr Edwards in 1817, may not be generally known, I shall briefly state, that the former shut up three toads in sealed boxes in plaster, which, after having been deposited for eighteen months in the Academy of Sciences, were opened and two of the toads were found to be living, one alone having died. Dr Edwards enclosed some toads totally in plaster, and absolutely, as far as he could, deprived them of air: they all lived many days, and much longer than those which were forced to remain under water. This singular result can only be accounted for on the supposition that air must have penetrated through the plaster.

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