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Figs. 2, 3. Vertical sections of agatised Petioles, composing the false bark on the trunk of Cycadites microphyllus, and of embryo Buds. In the Bud, Fig. 2. d. the division between the two woody circles is not distinct. In Fig. 3'. d. it is very obvious; but the intermediate circle of cellular tissue is represented only by a fine line. See V. I. p. 374, Note. and p. 376, Note. (Original.)

In the sections of Pl. 61, Figs. 2, 3, and Pl. 61, the following letters are used to indicate the same parts. a, cotton, or down; b, integument of petioles or scales; c, bundles of vessels; d, woody circles; e, imperfect woody circles; f, cellular tissue; g, embryo bud; h, gum vessels.*

PLATE 62. V. I. p. 374, Note.

Fig. 1. Longitudinal section of a Petiole of Zamia spiralis magnified two times. It exhibits four bundles of ⚫ vessels passing longitudinally through the cellular tissue, which is interspersed with gum vessels. V. I. p. 375. (Original.)

A. Transverse section of Fig. 1. magnified, and showing the irregular disposition of the bundles of vessels. (Original.)

c'. Magnified view of one of the bundles of vessels at A, c. (Original.)

B. c'. Magnified transverse section of a bundle of vessels in the petiole of Zamia horrida. (Original.) Fig. 2. Longitudinal section of a portion of an agatised petiole of Cycadites microphyllus, from Portland, magnified four times. The down or cotton at a, is

*These very beautiful and instructive sections were presented to me by Mr. Witham, being portions of a trunk which I had placed at his disposition.

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most beautifully preserved, and the integuments of the petiole b, longitudinal vessels e, and gum vessels f, correspond with those in Fig. 1. See V. I. p. 375, Note. (Original.)*

Fig. 3. Transverse section of a portion of the lowest Petioles, in Pl. 61, Fig. 3, b, c, magnified four times.

The disposition of the bundles of vessels is nearly parallel to the integument of the Petiole.†

d, Magnified portion of the double woody circle, within the Embryo bud, Pl. 61. Fig. 3. 'd.

d'. More highly magnified portion of the embryo double woody circle d.

c'. More highly magnified section of one of the bundles of vessels, adjacent to c.

These bundles of vessels, exhibit, in their transverse Section, a series of minute tubes, arranged in rows, and between these rows, opaque plates of compressed cellular tissue, resembling portions of medullary rays.

The fibrous structure of the integument is preserved in several parts of b. See V. I. p. 376, Note. (Original.).

* Mr. Robert Brown has noticed in the cellular tissue of a silicified trunk of Cycadites, portions of Calcedony bearing the form of extravasated gum within the trunks of recent Cycades. He has also recognised spiral vessels, in the laminated woody circle of a mature trunk of fossil Cycadites, and also in the laminated circle within a silicified bud of the same, near its origin.

A familiar example of a nearly similar disposition of bundles of vessels, passing into the Petiole or leaf-stalk, may be seen in the base of the fresh fallen leaves from a horse-chestnut tree, or in the scars on a cabbage-stalk, from which leaves have fallen off.

PLATE 63.* V. I. p. 377.

Fig. 1. Recent Pandanus, of S. America, twenty feet high, with its fruit attached. (Mirbel.)

Fig. 2. Fossil fruit of Podocarya, from the Inferior Oolite, near Charmouth, Dorset. Great part of the surface is covered with a stellated Epicarpium; the points of many seeds project in those parts (e) where the Epicarpium is wanting. (Original.)

Fig. 3. Reverse of Fig. 2. showing the seeds placed in

single cells (b) around the circumference of the fruit. These seeds stand on a congeries of foot-stalks (d) composed of long fibres, which terminate in the receptacle.(r) The surface of the receptacle is studded over with small disks, in which these foot-stalks originate. (Original.)

Fig. 4. Base of the same fruit, showing the transverse

section of the receptacle (r), and the summits of many abortive cells on the left side of the receptacle. (Original.)

Fig. 5. A single seed of Podocarya converted to carbonate of lime. Nat. size. (Original,)

Fig. 6. The same magnified.

(Original.)

Fig. 7. Transverse section of a seed magnified. Two lunate marks, of a darker colour than the other part. appear near its centre, f'. See Fig. 8. and the middle of Fig. 10. (Original.)

* Explanation of Letters of Reference.

a. Stellated tubercles, each one covering the apex of a single seed. b. Sections of the seed cells.

c. Bases of cells of which seeds have fallen.

d. Fibrous foot-stalks between the seeds and receptacle.

e. Apices of seeds uncovered.

f. Transverse section of seeds.

Fig. 8. Magnified portion of Fig. 3: showing a withered stigma in the centre of each hexagonal tubercle (a); beneath these tubercles is a longitudinal Section of the single cells (b), each containing one seed (ƒ); and in front of these cells are the hollow bases of . other cells (c, c) from which seeds have been removed. (Original.)

Fig. 9. Another magnified portion, showing the apices of many seeds (e) from which the Epicarpium has been removed. (Original.)

Fig. 10. Another magnified portion, showing at a, b, c,

more distinctly the same parts as at Fig, 8; and at d, the upper portion of the fibrous foot-stalks beneath the bases of the cells, c. (Original.)

Fig. 11. Summit of one of the drupes or groups of cells into which the fruit of the recent Pandanus is divided; showing an hexagonal disposition of the coronary tubercles, each bearing at its centre the remains of a stigma, as in the Podocarya. See Figs. 16. 17. (Original.)

Fig. 12. Exterior of a single seed-cell of Pandanus odoratissimus. (Jaquin. Frag. Bot. Pl. 14.)

Fig. 13. Section of a Drupe of Pandanus odoratissimus. The central cell containing a seed, is placed between two abortive cells. At the apex of each cell in this drupe (a) is a withered stigma. (Roxborough Coromandel. Pl. 96.)

Figs. 14, 15. Sections of a Drupe of Pandanus odoratissimus, showing the seeds within the prolific cells surrounded by a hard nut. Beneath this nut is a mass of rigid fibres like those beneath the seeds of Podocarya. (Jaquin.)

Fig. 16. Summit at the hexagonal tubercle at the apex of a cell of Pandanus humilis, with a withered stigma. in the centre. (Jaquin. Frag. Bot. Pl. 14.)

Fig. 17. Side view of another tubercle of the same (Jaquin. Frag. Bot. Pl. 14.)

species.

PLATE 64. V. I. p. 387.

Fig. 1. Fossil leaf of a Flabelliform Palm from the Gypsum of Aix in Provence. (Brongniart.)

Fig. 2. Upper portion of the Fossil trunk of a tree allied to palms (nearly four feet in diameter,) from the Calcaire Grossier at Vaillet, near Soissons, preserved in the Museum d'Hist. Nat. at Paris. See p. 387. Note. (Brongniart.)

PLATE 65. V. I. p. 396.

Fig. 1. Section across the Wednesbury Coal basin from Dudley to Walsall. (Jukes.)

The extensive Iron foundries which cover the surface of this district, and the greater part of the manufactures in the adjacent town of Birmingham, originate in the Coal and Iron ore, with which the strata of shale in this Coal basin are richly loaded.

The Dudley Limestone here found immediately below the Coal formation, occurs usually at a much greater depth in the series. The Mountain Limestone, Old red Sandstone, and Ludlow rocks, are here wanting. (See Pl. 66, Fig. 1.) Fig. 2. Section, showing the basin-shaped disposition of the Carboniferous strata in S. Wales. (Rev. W. D. Conybeare.)

The richest beds of Coal and Iron ore are placed almost immediately above the Mountain limestone. (See pp. 59, 396.) It is to this district that our Posterity must look for their future supplies of Coals, and transfer the site of their Manufactures, when

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