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with such a bare hypothesis, if it had not already awakened the 6 curiosity of many to a class of facts extremely interesting, although

too few, in number to admit as, yet of extensive generalization. The uniformity of ancient climate can only be established when scientific researches shall have been further prosecuted in every zone, from the territories of our new allies the Esquimaux, to the southern boundaries of our Indian empire.

Before we finally take leave of organic remains, we must not forget that Professor Buckland has in this volume made particular mention of the first example of a mammiferous quadruped occur-, ring in an ancient secondary rock. The remains of land quadrupeds had never before been observed in any

formation ancient as the chalk: but in the calcareous slate. of Stonesfield in Oxfordshire, which lies in the upper part of the lowest division of oolitic rocks, Dr. Buckland notes. Two portions of the jaw of the Didelphis or Opossum, being of the size of a small kangaroo rat, and belonging to a family which now exists chiefly. in America, Southern Asia, and New Holland.... I refer (he adds); the fossil in question to this family on the authority of M. Cuvier who has examined it.'

As this fact is completely at variance with all preceding observations, it is not surprizing that it has been received with some scepticism. M. Constant Prevost,* who has himself visited Stonesfield, has lately published a memoir, in which every argument that can be urged to invalidate Dr. Buckland's opinion is put forth with great ability and with a spirit of fairness, but all this has not in the least shaken our reliance on the accuracy of the statement. In the first place, it is admitted that the remains in question were decidedly imbedded in the Stonesfield slate. To this stratum, in working the quarries at Stonesfield, they descend by vertical shafts through a solid rock of corn-brash and stratified clay more than forty feet thick.'+ M. Cuvier, who has re-examined the fossil in question since the objection was started, still pronounces the animál to have been mammiferous, resembling an opossum, although of an extinct genus, and differing from all known carnivorous mammalia in having ten teeth in a series in the lower jaw. M. Constant Prevost remarks, that the relations of the slate in question, both with the superincumbent and subjacent beds, are obscure at Stonesfield; that doubts have been expressed by different English writers as to the exact position it occupies among the minor subdivisions of the oolitic series; that the schistose oolitic rocks, supposed by Dr. Buckland and other English geologists

Observations sur les Schistes calc. colit. de Stonesfield. Ann. des Sciences Nat. April, 1825. 1 p. 393. VOL. XXXIV. NO. LXVIII.

L L

to

free warrens; the numerous fruits of tenures, as fines on death and alienations, heriots, profits of courts, &c. common of pasture ; being a privilege to the tenants of depasturing over their lord's waste.'

The profits of tenure he proposes to discuss under the head of copyholds, to which they are now principally confined. And, as to rights of pasture,

the opinion,' he says, 'both of the legislature and the public, upon the policy of this privilege, has been already expressed by the gereral Inclosure Act of 41 Geo. III. and the numerous local inclosure acts which have passed and been acted upon both before and since; to such an extent, indeed, as to have materially diminished the general quantity of waste land.'

The author then briefly alludes to the peculiar servitude (still following his own mode of classification) of tithes ; but refers us to a subsequent division of his work as containing his reason (which is of a prudential character) for declining a full discussion of it.

His third title embraces the different modifications of interests in real property, as at present acknowledged. -Of these the first is a fee-simple; the greatest estate known in our law. The second consists of estates tail and other modes of settlement. The operation of the law of entail for this purpose, though traced through all its singular obliquities, is scarcely so curious as another and more modern mode of settlement which he has thus characterized,

It is effected by what are called springing uses in deeds, and executory devises in wills. The rigid law of tenures allowed of no limitations after a fee; but uses, adapted as they were to the exigencies of more recent times, and devises, which followed them in their modifications, admitted of this fee being rendered defeasible on certain events, and another being substituted for it. After much uncertainty as to the extent to which these substitutionary estates might be carried, they were finally limited to the period of a life or lives in being, and twenty-one years afterwards, with a further allowance for the gestation of conceited issue (about ten months). This limit was fixed by an alleged analogy to settlements by entail on the parent for life, with remainder to his unborn eldest son in tail, and with any extent of remainders over for life and in tail; but all of which might be barred by the son, either alone, or concurrently with the parents if living, suffering a recovery on attaining his majority, to which period the above limitation of twenty-one years was meant to relate.

* An essential variance was, however, in time discovered between the two modes; inasmuch as, in springing uses and executory devises, the lives were not required to take corresponding interests, or to be other"wise connected with the estate, but might be introduced as mere pominees, for the purpose of protracting the power of alienation. This glefect was taken advantage of to an extraordinary extent by the late Mr.

Thellusson,

as well as water-birds and oviparous quadrupeds, we may fairly presume. That they sometinies carried them into the open sea and mingled them with marine shells and zoophytes is no less probable. Such admixtures would necessarily be limited in extent, as is the case at Stonesfield; for rivers like the Amazon and Oronoco, which may be supposed extensively to affect the sea at a great distance from land, can never be numerous. That phenomena like those at Stonesfield have seldom presented themselves, appears less remarkable, when we reflect that we have examined the organic remains of continuous formations in a few insulated spots only. The analogy of the fossils of Stonesfield and Cuckfield in Sussex tends to contirm the antiquity of the former, and noti to render it more problematical, ahhough M. Prevost, not being in possession of facts since ascertained, has so contended. Fortunately there is no question whatever as to the position of the Tilgate beds. Their relations can be studied not only at Cuckfield and other localities in the interior of the country, but in the cliffs at Hastings. They are certainly of a date anterior to the chalk and green sand. If mammiferous quadrupeds of the order cetacea oceur, as Dr. Buckland mentions, in so old a stratum as that of Cuckfield, the possibility of their presence in the Stonesfield slate and im the corn-brash limestone in Oxfordshire, in both of which they are declared to have been found, ought to be admitted with little reluctance.* But if marine mammalia were then created, it is not improbable that terrestrial animals of the same class existed; and although it is surprizing that one example only has yet been discovered, we must not forget how large a portion of the European secondary formations are entirely marine, while, on the other hand, no bones of quadrupeds have yet been procured from the lower freshwater formation in Hampshire, although, in fossil contents and geological position, it is so analogous to the freshwater rocks in France and Germany, which inclose such multitudes of extinct mammalia.

The analogy between the fossils of Stonesfield and Cuckfield was first observed by Mr. Mantell,t and is now placed in so strong a light by Dr. Buckland that many readers may perhaps be misled, like M. Prevost, into a belief of their almost perfect identity. But, in the first place, there is a total discrepancy in their fossil shells; those of Stonesfield being exclusively marine and sometimes accompanied by zoophytes, those of Cuckfield being all analogous to freshwater testacea. The fossil Plants of the two localities differ generically. At Stonesfield a large proportion are decidedly marine, algæ, fuci, &c.; while others, like

Page 392.

+ Geology of Sussex, p. 59, 60.

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Page 394.,

all those of Cuckfield, are terrestrial, lacustrine or fluviatile. We have not sufficient information concerning the bones, teeth, and palates of the various fishes and sharks to decide that any two of them : agree in species. This remark applies with still greater force to the remains of cetacea and birds. No Didelphis has yet been found in the Tilgate . beds, no Iguanodon at Stonesfield. That the bones of gigantic dimensions procured at Cuckfield belong strictly to the same genus as the Megalosaurus of Stonesfield, we have little doubt, although the bones of the skeleton bitherto found in actual apposition at either place are so few, that to determine this point, much less to decide on their specific identity, is impossible. The same may be said of the Piesiosaurus and Crocodile. · Although the tortoises are numerous in both localities, none have yet been shown to be of the same species. The correspondence, in short, of the remains at Stonesfield and Tilgate Forest, imbedded in strata totally dissimilar in mineralogical characters, is what we might expect to find between the same formations and the deltas of the Nile, Ganges, and all large rivers of the present day in hot climates.

We have only space to allude briefly to some of the geological papers in this volume. They contain a great mass of new information, and we cannot but express our regret that the Geological Society, possessing so many zealous members, and engaged in promoting a science so fertile in new discoveries, should have permitted a lapse of two years to intervene between the completion of the volume we have been reviewing, and a new part; published wbilst we are concluding this Article. There are two papers by Mr. Colebrooke on the valley of the Sutluj river, in the Himalaya mountains, and on the north-eastern border of Bengal, and another by Mr. Fraser on the country between Delhi and Bombay, which, when considered together, are sufficient to establish a remarkable resemblance in the leading geological features of the vast continent of India to that of Europe and North America. The primary rocks in Central India and in the Himalaya mountains are identical in mineralogical character with those of the Alps, and, in fact, of all primary ranges in the world. The striking analogy of the fossils from the north-east of Bengal to those of the formations above the chalk in England, is extremely curious, and quite consistent with the conclusions already deduced from the organic remains procured in the strata near Madras, and deposited with specimens from various parts of India in the museum of the Geological Society. The identity of the başalts and amygdaloids, and other varieties of trap brought by Mr. Fraser from India, with those found in similar situations in Englaňd, is no less interesting; and lastly, the coal formation,

consisting

consisting of micaceous sandstone, bituminous shale and coal,:on the banks of the Tista and Subuk rivers, which descend from the Bhotan mountains, cannot fail to recal to the mind of the geologist the ancient coal formations of Europe and North America,

The joint paper on the south-western coal district of England, by Dr. Buckland and Mr. Conybeare, deserves attention no less for the variety than the importance of its contents. It establishes the relations of some of the most remarkable British rocks, and furnishes us with an accurate description of the physical geography of a large district. It may also be regarded as a statistical document of the first authority, containing numerous detailed sections of collieries and a determination of the limits of the coal fields of Bristol, the Forest of Dean, and several of minor extent, by which their present productive powers and future resources may be estimated; lastly, it supplies data, founded on multiplied observations, which may direct the search of the miner to new discoveries, and often prevent a fruitless expenditure of capital in insuccessful trials. The Bristol coal district, illustrated by the beautiful map and sections accompanying this memoir, may be pointed out to the student as full of instruction, for a great variety of formations are here comprized within a small space; and, while a knowledge of their regular order of superposition may be easily obtained, instructive examples occur of the occasional absence of different members of the series and of the leading features of disturbance exhibited on so immense a scale in high mountain chains. We regard this country also as the more entitled to the student's preference, because trap rocks, so abundant in the coal fields of Scotland and the north of England, are here entirely wanting, at least in every formation from the old red sandstone to the oolite inclusive. Geologists have in general commenced their investigations in countries where the derangement of the strata was greatest, and all the phenomena attending them the most complicated. They have studied the exceptions before the rule; and when to this we add disregard to the present operations of nature, whether with reference to aqueous deposits or volcanic products, we cannot be surprized that the theories of the earlier professors of this science, even when founded exclusively on facts and observations, were contradictory; and that the generalizations of Werner and Hutton, though bearing impressed upon them the decided marks of genius, have required considerable modifications.

Two great series of rocks occupy the south-western coal district. In the first, comprizing the lowest and most ancient formations, (the greywacke transition limestone, old red sandstone, mountain limestone and coal measures,) the strata are highly inLL 3

clined,

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