334 
Arher . — On the Nature of the ‘ Blade ’ in 
more recent writers. 1 Eichler interprets the leaves of the Cyclanthaceae 
as owing their form to folding, the agency to which he also attributes the 
plicated appearance of the Palm-leaf. I have found, however, on studying 
Figs. 5-7. Figs. 5 a-e, Areca sapida, Soland., series of transverse sections (X47) through 
one leaf, from sheath, Fig. 5 A, to plicate ‘lamina’, Fig. 5 E ; m.b ., median bundle; l. x , l. 2) /. 3 , 
/'. 2 , l'. 3 , principal lateral bundles. In Figs. 5 C-E the invaginations are shown which penetrate 
between the bundles of the petiole, Fig. 5 B. Figs. 6 a-e, Oreodoxa regia , H. B. et K., sections from 
a series through the first foliage leaf (third plumular leaf) of a seedling (X14). Lettering of 
bundles as in Fig. 5 ; Fig. 6 A, petiole ; Fig. 6 B, first signs of invaginations indicated by arrows ; 
Fig. 6c, half the ‘lamina’, showing eventual distribution of bundles. Figs. 7 A, B, Carludovica 
Plumerii , Kunth, transverse sections of young leaf passing through sheath, Fig. 7 A, and regions 
where invagination begins, Fig. 7 B ( x 14). 
the leaves of Carludovica , that here, as in the Palms, the process by which 
the ‘ lamina 5 arises is rather to be described &s invagination of the petiolar 
tissues. In a young leaf of C arludovica Plumerii , Kunth, which I examined, 
there was no sharp distinction between sheath (Fig. 7 a) and petiole, but 
1 Hirmer, M. (1919). 
