Cambium in Monocotyledons. V. 253 
Figs. 1-8. (Lettering throughout as follows : p.x., protoxylem ; p.ph., protophloem ; p.p 
palisade parenchyma; u.e upper epidermis ; l.e., lower epidermis.) Fig. i, Rhapis humilis , Blume, 
bundle from transverse section of stem close to apex (X318). Fig. 2, Calla palustris, L., bundle 
from transverse section of petiole of very young leaf ( x 318). Fig. 3, Arum italicum , Mill. ; Fig. 3 a, 
median bundle from transverse section of lamina of very young leaf ( x 193) ; Fig. 3 B, lateral bundle 
from transverse section of petiole of older leaf ( x 193) ; m.x., primary metaxylem ; x.%, secondary xylem. 
Fig. 4, Potamogeton natans, L., lateral bundle from transverse section of very young petiole (x 318). 
Fig. 5, Apotiogeton distachyu? 7 i, Thunb , principal bundle from transverse section of very young 
inflorescence axis ( x 318). Fig. 6, Sagittaria sagittifolia , L., transverse section of very young petiole ; 
m.b., median bundle ; lac., lacunae, of which only three are yet visible ( x 193). Fig. 7, Stratiotes 
aloides, L., bundle from transverse section of base of very young leaf ( x 318). Fig. 8, Hydrocharis 
Morsus-ranae, L., median bundle from transverse section of limb of very young leaf (x 318). 
