Fig. 10. a, Stellate hairs from the leaf of a species of Hibiscus; b, a scale of
the calyx of Elæagnus argentea; c, a hair of Chrysophyllum Cainito.
Fig. 11. Reticulated cellular tissue from the testa of Maurandya Barclayana.
Fig. 12. Spiral oblong cellules lying among the parenchyma of the leaf of
Oncidium altissimum.

Fig. 13. Deep columnar cellules, with parallel fibres from the endothecium of
Calla æthiopica; the top of each cell being flat; after Purkinje.

Fig. 14. Arched fibres connected by a membrane in the endothecium of Nymphæa alba; after Purkinje.

Fig. 15. Flat oval cellules, with marginal incisions in the endothecium of Phlomis fruticosa; after Purkinje.

Fig. 16. One of the elastic fibres upon the testa of Collomia linearis, unrolled spirally, and lying within its mucous sheath; magnified 500 times.

Fig. 17. A part of one of the elaters of a Jungermannia, showing a broad spiral fibre loosely twisted inside a transparent tubular membrane, with a dilated thickened mouth.

Fig. 18. Convex membranes, with lateral radiating fibres, forming together imperfect cells; in the endothecium of Veronica perfoliata; after Purkinje. Fig. 19. Radiating fibres, in the place of cellules in the endothecium of Polygala chamæbuxus; after Purkinje.

Fig. 20. Prismatical depressed cells, with straight fibres on the walls; from the endothecium of Polygala speciosa; after Purkinje.

PLATE II.

Fig. 1. Common woody fibre; a, slightly magnified; b, very highly magnified, and shown as seen by transmitted light; the extremities only are seen: c, cellular tissue.

Fig. 2. Woody fibre from the leaf of Oncidium altissimum, from a preparation by Mr. Griffith. In this there are small tubercles growing from the surface of some of the fibres, irregularly, or arranged in a spiral direction; a is magnified 180 times; at b, which is magnified 350 times, the form of the tubercles is more distinctly shown; and it is seen that small granules are contained within the fibre.

Fig. 3. The dotted ducts of Zamia horrida. The little oval spaces that have been supposed to be holes, are shown to be opaque; most of them are oblique ; but some of them are exactly transverse, rounder, and have a distinct line passing through their longer axis.

Fig. 4. Woody fibre from the stem of Calycanthus floridus: in this the sides of the tubes are marked with small oval dots, exactly as in Zamia.

Fig. 5. A minute portion of a section of the wood of a species of Gnetum from Tavoy; a, woody fibre, filled with loose and rather angular particles of greenish matter; b, glandular woody fibre, showing its large size in proportion to the other, and the appearance of its glands.

Fig. 6. A vertical radiant section of the wood of yew, magnified 250 times; after Kieser; showing what he calls the spiral porous cells. The spires vary from one to four in each cell; and the glands, when present, are always situated between the spires, as at a, b, e, and g. Some of the cellules have no glands, as c, d, f, h, i. The yew has true spiral vessels besides these.

Fig. 7. A small portion of a vessel in the wood of an Ephedra from Chili,

taken from the vicinity of the medullary sheath: its membrane is distinctly perforated at the upper part with oval holes: at the lower part the place of these holes is occupied by glands like those of Gnetum, in fig. 5.; or of Abies, in fig. 8. It would therefore seem, that the oval holes in the membrane of Ephedra are places from which the glands have fallen. Magnified 350 times. Fig. 8. A vertical radiant section of the wood of Pinus Abies, showing the glands upon the walls of woody fibre, magnified 520 times; after Kieser; but corrected by showing that the glands are convex, and the supposed pores in their centre often opaque.

Fig. 9. The termination of a spiral vessel, extracted from the root of a hyacinth by Mr. Valentine: this shows distinctly the enveloping membrane.

Fig. 10. A fragment of a spiral vessel, bent abruptly to show that it is cylindrical and not flat; magnified 500 times.

Fig. 11. A spiral vessel, with each twist composed of four fibres, from the stem of Nepenthes distillatoria. This is the largest spiral vessel yet known.

Fig. 12. A minute portion of a transverse section of an Indian tree, showing a medullary ray, a; the mouths of several bundles of ducts, bbb; and the ends of the woody fibre, c c, d d, in which the latter are imbedded. The wood of

this plant is exceedingly compact; evidently owing to the denseness and stoutness of the woody fibre.

Fig. 13. Two vessels from the stem of Impatiens balsamina; magnified 130 times; after Kieser a is a duct, with the spires broken in some places, and inosculating in others, so as to form the reticulated vessel of this author; b, a spiral vessel, with the spires broken at the top into rings.

Fig. 14. A horizontal section of the stem of Tropæolum majus, magnified 130 times; after Kieser. This is to show the intercellular passages, which are unusually large; at a they are empty; at b filled.

Fig. 15. A tangental section of Sassafras wood, magnified 130 times; after Kieser; a a, two banded dotted vessels; or, as Kieser calls them, punctuated spiral vessels; bb, the mouths of the medullary rays, showing how they are connected with the bark.

Fig. 16. Dr. Bischoff's representation of the manner in which spiral vessels pass successively into annular and dotted ducts. This figure is imaginary; but Dr. Bischoff asserts that he has actually seen such a vessel in the garden spinage. (Spinacia oleracea.)

Fig. 17. Two sorts of dotted vessels from the wood of Phaseolus vulgaris, magnified 130 times; after Kieser: a, has the bands much more nearly approximated than b, in which the spaces between the bands is almost fusiform. Fig. 18. A bundle of ducts from the stem of a Lycopodium; from a preparation by Mr. Griffith: this shows the manner in which such vessels are packed together when in situ, and their terminations.

Fig. 19. A dotted duct and short woody fibre from the stem of Phytocrene gigantea; from a drawing by Mr. Griffith, in Dr. Wallich's Planta Asiatica,

t. 216.

Fig. 20. The same, from the same authority, showing that this sort of vessel is really composed of short cylindrical cellules, placed end to end, and opening into each other.

Fig. 21. A section of the cyst, or receptacle of oil in the rind of a lemon, showing that it is a mere cavity built up of cellular tissue.

M M

PLATE III.

Fig. 1. A cluster of six-sided air-cells from the stem of Limnocharis Plumieri: they are formed entirely of prismatical cells; a a, partitions dividing the air cells in two.

Fig. 2. A partition or diaphragm of the last-mentioned plant, showing the open passages that exist at the angles of the cells. When dry the rims of the passages are dark, as at a: when immersed in water, the dark rim disappears, and the whole partition has the uniform appearance of b.

a,

Fig. 3. A portion of the cuticle, and a stoma, of the leaf of Oncidium altissimum ; the stoma, formed of two parallel glands or cells, which open by curving outwards. In this plant the stomata are very minute and few: on the membrane of each mesh of the cuticle are found sticking from four to six spherical semi-transparent green globules.

Fig. 4. Stomata of Strobilanthes Sabiniana. They are very large, and crowded together in an irregular manner.

Fig. 5. Ditto of Croton variegatum: this is an instance of a cuticle with sinuous lines. The orifice of each stoma is closed up with brownish matter.

Fig. 6. A stoma of Canna iridiflora.

Fig. 7. A cavity beneath the cuticle, in the parenchyma of Begonia sanguinea ; seen from the inside, so that the cuticle is farthest from the eye. It is divided by sub-cylindrical cellules into five spaces, in each of which there lies a

stoma.

Fig. 8. One of the stomata of the same, more magnified, and showing that the medial line does not touch either end, and that the cavity of the stoma is filled with granular matter.

Fig. 9. Stomata of the under side of the leaf of Caladium esculentum, with a portion of cuticle. These appear to be somewhat angular cellules, occupying the centre of every area of the cuticle. The stoma consists of an oval space, in the centre of which is a narrow cleft, with a border distinctly coloured orange or brownish, and having no communication with the circumference: the space between the cleft and the latter filled with a pale green granular substance. The cleft is sometimes seen closed, as at a, and then there is scarcely any appearance of a border.

Fig. 10. Cuticle and stomata of Yucca gloriosa: the latter lie in square areolæ, and consist of two parallelograms lying parallel with each other. Small sphe

roidal bodies, having a luminous appearance under the microscope, stick here and there to the inside of the cuticle.

Fig. 11. Stomata of Limnocharis Plumicri. These also lie in square areolæ, but they have the ordinary structure: they are found in different degrees of openness, or even quite closed, upon a small piece of the same specimen. Fig. 12. Stamen of Lemna trisulca: anthers bursting vertically.

Fig. 13. Stamen of Polygonum Convolvulus; a, seen in front; b, from behind; the connectivum of the anther.

c,

Fig. 14. Stamen of Correa alba; a, seen in front; b, from behind.

Fig. 15. Stamen of Stachys sylvatica; a, filament; b, connectivum; c, anther, its lobes separated at the base by the connectivum.

Fig. 16. Anther of Alchemilla arvensis; one-celled, and bursting transversely. Fig. 17. Stamen of Scrophularia chrysanthemifolia; a, part of the filament, and