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 Caly- 

 canthus 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 ; &, ditto of the lower surface ; c, stomates 

 cut through in different directions ; these last are seen to open into cavities 

 in the parenchyma ; d y upper layer of parenchyma ; e, intermediate ditto ; 

 /, 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 ; &, 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, /, 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 

 irregular 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 j 6, a hair 



