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EXPLANATION OF THE PLATES.

N. B. All the figures in the plates. of which the following is an explanation, are more or less magnified: the drawings from which they have been prepared are in all cases original, except where it is stated to the contrary.

PLATE I.

Fig. 1. A small portion of a section of the cellular tissue of the pith of Calycanthus floridus, showing the pore-like spots upon the membrane. Fig. 2. A section of the leaf of Lilium candidum; after A. Brongniart: a, epidermis of the upper surface; b, ditto of the lower surface; c, stomata cut through in different directions; these last are seen to open into cavities in the parenchyma; d, upper layer of parenchyma; e, intermediate ditto; f, lower ditto. Fig. 3. Cubical cellular tissue, passing gradually into prismatical, from the stem of the gourd, cut vertically; after Kieser.

Fig. 4. Fibres forming arches in the endothecium of Linaria Cymbalaria; after Purkinje.

Fig. 5. Fusiform cellules in the wood of a young branch of Viscum album; after Kieser: a, common hexagonal cells of the pith, with grains of amydon sticking to their sides; b, fusiform cellules, considered by Kieser to be pierced with holes; c, other cells of the same figure, with lines of dots spirally arranged on the membrane; d, others, in which the dots are run into lines; e, f, others, in which the cellules have all the appearance of short spiral vessels. Kieser considers these not as spiral vessels, but as cellules of a peculiar kind, replacing spiral vessels in the Viscum.

Fig. 6. A portion of the cuticle of Billbergia amoena, with the membrane torn on one side, showing that it does not tear with an even edge, but breaks into little teeth.

Fig. 7. Muriform cellular tissue, forming the medullary processes of Platanus occidentalis. Each cellule contains particles of brownish matter of very irre

gular size and form. Fig. 8. a, Glandular hairs of the peduncle of Primula sinensis; 1. the glandular apex more highly magnified, with a particle of the viscid secretion of the species on its point; 2, the apex of another hair, showing that the end is open, a conical piece of the viscid secretion lying in the orifice; b, a hair of Dorstenia, showing the cellular base from which it arises, and that it consists of a single hollow conical curved cell.

Fig. 9. A branched hair from the cilia of the leaf of a species of Verbascum. Fig. A. A simple coloured hair in Dichorizandra rufa.

Fig. B. A hair with tumid articulations from the leaf of Gesneria tuberosa.