474 
Agnes Arber .— The Phyllode Theory of 
Figs. 1-5. (In all diagrams of sections, xylem is represented black, phloem white, and fibres, 
/, dotted.) Fig. 1 a and B. Acacia scirpifolia , Meissn. Fig. 1 a. Apical region of shoot with 
cylindrical phyllodes (reduced). Fig. 1 b. Transverse section of phyllode (x 30); pal. par. = pali¬ 
sade parenchyma. Fig. 2 A, b, c, d. Acacia neriifolia , A. Cunn. Fig. 2 A. Upper part of seed¬ 
ling (reduced); a and b = normal leaves; c = leaf with petiole slightly expanded ; d-g = 
phyllodes ; p.m.r. = pseudo-midrib. Fig. 2 B. Transverse section of petiole of a leaf lower on the 
axis than leaf a. Fig. 2 c. Transverse section of petiole of leaf c; m.b. = median bundle; m.l. — main 
laterals. Fig. 2 d. Transverse section of phyllode f; p.m.r. = pseudo-midrib, derived from the two 
main laterals (m.l.) ; m.b. = median bundle. Figs. 2 B-2 D x 30. Fig. 3 A and B. Oxalis bupleuri- 
folia , A. St. Hil. Fig. 3 a. Apical region of shoot (reduced). The successive leaves, a-d , show 
progressive reduction of lamina, which in e and f is entirely lost. Fig. 3 B. Transverse section of 
part of phyllode including midrib, m.r. ( x 30). Fig. 4. Ranunculus Ficaria, L. Part of basal region 
of plant to show two prophylls (pr.) corresponding to sheathing bases (s) of normal leaves. Fig. 5 A, b, c. 
Ribes nigrum, L. Fig. 5 a (i)-(v). Successive leaves of bud, showing transitions from bud-scale to 
normal leaf (reduced). Fig. 5 b. Transverse section of petiole ; g = glandular emergence ( x 17), 
Fig. 5 c. Transverse section of bud-scale (incomplete); m.b. = median bundle (x 17). 
