336 Arber . — On the Nature of the ‘ Blade ’ in 
‘ lamina’ are seen on the adaxial side of the petiole,/^. ; Fig. 8 e, cordate lobes being detached by 
invagination; Figs. 8f and G, Mamina’; Figs. ,8 H and I, solid apex of leaf, in which vascular j 
bundles unite to a plexus (shaded). Figs. 9 a-f, Arum italicum , Mill., series of transverse 
sections through one leaf ( x 23) ; Fig. 9 B passes through the extreme upper limit of the sheath, .y. ; 
Fig. 9D shdws the detachment of the auricles, a. and a'., by means of invaginations. (Figs. 9 A-F 
slightly reconstructed as the sections were broken.) Figs, ioa-e, Arum maculatum, L., series of 
transverse sections through first plumular leaf of seedling, from preparations in Miss Sargant’s i 
collection (X47); Figs. 10 A and 10 B, sheath; Fig. 10 C, petiole; Fig. iod, Mamina’; Fig. 10 E, 
solid apex. Figs, iia^-d, Epipremnum mirabile , Schott, series of transverse sections through 
a single leaf, sheath and vascular bundles omitted ( x 47) ; Fig. 1 1 A, just below level of attachment 
of auricles, a. and to petiole; Fig. 11 b, level at which auricles are connected with petiole : 
Figs. 11 C and D, ‘ lamina *. (Fig. 11 A, slightly reconstructed as section broken.) Figs. 12 A-C, 
Pistia Stratioies, L., series of transverse sections through one young leaf ( x 14), leaf-sheath, ligule, 
hairs, and lacunae, omitted ; Fig. 1 2 a, narrow basal region ; Fig. 1 2 c, broader distal region. 
