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 im-
perfect 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. A section of pitted cellular tissue, showing on one side the matter of lignification separate from the elementary membrane; in the lines where the cells unite this is not shown, the membrane being so thin as to be inappreciable: a a a are pits in the sides of cells, corresponding with similar pits in the neighbouring cells; b shows that the pits are sometimes depressions without any thing to answer to them on the opposite side.

Fig. 2. An ideal figure of part of a tube of bothrenchyma, showing that the apparent holes are mere pits in the interior.

Fig. 3. A section of coniferous wood: a, glandular pleurenchyma; b, spiral vessels; c, prismatical parenchyma, containing chlorophyll.

Fig. 4. A transverse section of two complete tubes of glandular pleurenchyma, to show that the glands are thin spaces in the sides of contiguous tubes, through which light passes in the direction of a a.

Fig. 5. A front view of coniferous glands in a young state.

Fig. 6. A very highly magnified view of such glands, showing that their surface is marked by concentric circles.

Fig. 7. A front view of a coniferous gland, partially covered by the matter of lignification.

Fig. 8. A profile view of the same.

Fig. 9. A simple or one-threaded spiral vessel, partly unrolled, with its termination.

Fig. 10. A bent portion of the spire of the latter, to show that elementary fibre is cylindrical.

Fig. 11. A compound or many-threaded spiral vessel, partly unrolled, with its

terminations.

Fig. 12. A longitudinal section of a portion of a stem, showing various kinds of tissue a and g, tubes of cinenchyma or laticiferous tissue; b, cylindrical parenchyma; c, an annular duct; d, an annular duct of larger size, with its spires more broken; e, cylindrical parenchyma containing amylaceous granules; f, a reticulated duct; h, oblong parenchyma containing amylaceous granules.

Fig. 13. Joints of a hair, showing the capillary cinenchyma in which cyclosis takes place; a, cytoblasts; the arrows indicate the direction of the currents. Fig. 14. Two joints of a hair of Tradescantia in a dead state, to show the collapsed appearance of the cells (b b) which are enclosed within the external cavity of organic mucus, and over which the currents of cyclosis are maintained; a, a cytoblast.

Fig. 15. A bundle of closed ducts from the stem of a Lycopodium; after a preparation by Mr. Griffith. Here is seen the manner in which such vessels are packed in situ, together with their terminations.

Fig. 16. A portion of cinenchyma, or laticiferous tissue, from the stipule of the Ficus elastica, showing the anastomoses; after Schultz.

Fig. 17. One of the anastomoses of cinenchyma, surrounded by thin-sided oblong parenchyma.

Fig. 18. A stinging hair, in which cyclosis is going on, the direction of the currents being indicated by arrows.

Fig. 19. An anastomosis in the cinenchyma of a Euphorbia, with two of the double-headed bodies supposed to be amylaceous; a a represent the mouths of the cinenchyma.

Fig. 20. Glandular pleurenchyma of Sphærostema propinquum.

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 aircells 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.

Fig. 3. A portion of the epidermis, and a stoma, of the leaf of Oncidium altissimum; a, 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 epidermis 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 an epidermis 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 epidermis, in the parenchyma of Begonia sanguinea seen from the inside, so that the epidermis is farthest from the eye. It is divided by sub-cylindrical cellules into five spaces, in each of which there lies

a stoma.