io6 Lee.— The Morphology of Leaf -fall. 
EXPLANATION OF FIGURES IN PLATES IV-VI. 
Illustrating Mr. Lee’s paper on Leaf-fail. 
The lettering applies also to Text-figures 1-20. 
a.b. = axillary bud. 
c.c. — crystal cells. 
c. = parenchymatous cells dividing to form 
Protective-cambium. 
ca. — Protective-cambium. 
cut. = cuticle. 
e.s. — exposed surface of scar. 
ep. — epidermis. 
g. — ground tissue of leaf-base which later 
will form the Protective-layer. 
Lig. = Lignified-layer. 
L. P. ~ ligno-suberized Protective-layer. 
P.pd. — first-formed Protective-periderm. 
P. pd. 1 — Protective-periderm formed in sub- 
sequent years. 
p. 
— cells of petiole. 
ph. 
= phelloderm of Protective- periderm. 
p.s. 
= cells which for a time retain their 
cellulose character. 
rt. 
— cortical cells. 
scl. 
= sclerenchyma accompanying leaf-trace. 
S.L. 
= Separation-layer. 
st. -pd. 
— periderm of stem. 
ty. 
= tyloses. 
ty\ 
= tyloses dividing to form JProtective- 
cambium. 
u. Z. P. 
= Protective-layer, not yet ligno- 
suberized. 
V. 
— vessels containing tyloses. 
V. B. 
= leaf-trace. 
Fig. 1. Castanea sativa. Longitudinal section of portion of leaf-base showing swelling of 
cell-walls of Separation-layer {S. Li) previous to separation. 
Fig. 2. Castanea sativa. Part of longitudinal section of scar showing formation of Protective- 
cambium. 
Fig. 3. Ribes sanguineum. Part of longitudinal section of leaf-base just previous to leaf-fall. 
Fig. 4. Tilia europaea. Longitudinal section of periderm beneath old scar, showing well- 
formed phelloderm {phi) 
Fig. 5. Betnla verrucosa. Part of longitudinal section of leaf-base just before leaf-fail. 
Fig. 6. Salix Caprea . Part of longitudinal section of leaf-base at time of leaf-fall. 
Fig. 7. Salix Caprea. Part of longitudinal section of first-year scar showing internal cuticle 
{cut O'), gum = deposition of gummy lignin on surface of scar. 
Fig. 8. Celtis occidentalis. Part of Protective-periderm in longitudinal section, co. = cork. 
Fig, 9. Celtis occidentalis. Isolated lignified crystal cells from Protective-layer, crys. — crystal 
of calcium oxalate, f. = film of lignin round crystal. 
Fig. 10. Halesia tet rapt era. Part of longitudinal section of leaf-base just previous to leaf-fall. 
Fig. 11. Rhus typhina. Portion of longitudinal section of leaf-base showing the continuation 
of the Separation-layer {S. L .) by division of 4 tyloses * within the resin duct. iy 1 . ■= 4 tyloses ’ 
becoming ligno-suberized. ty 2 . = 4 tyloses ’ dividing to form Separation layer, wa. — wall of 
resin duct. 
Fig. 12. Rhus typhina. Part of longitudinal section of leaf-scar showing origin of Protective- 
cambium {ca.) by division of cells, including tyloses, v 1 . = vessels which have become ruptured in 
consequence of growth and division of tyloses. 
Fig. 13. Rhus typhina. Transverse section of resin duct. tyl. = 4 tyloses’ in resin duct. 
Fig. 14. Rhus typhina. Longitudinal section of resin duct. 
Fig. 15. Mortis alba. Part of longitudinal section of leaf-base showing latex-tube traversing 
the Protective-layer (Z, Pi), wa. — wall in latex tube above Protective-layer. 
Fig. 16. Morns alba. Latex tubes with walls {wa.). Arrows show position of Protective-layer. 
Fig. 17. Ficus Carica. Latex tubes, a.b. and a x b l show position of Protective-layer. 
Fig. 18. Celastrus articulatus. Part of longitudinal section of leaf-base. 
