1122 
MichelL — On Ceraria and Portulacaria. 
EXPLANATION OF PLATE XCVIII. 
Illustrating Miss Michell’s paper on Ceraria and Portulacaria. 
Fig. i. Transverse section of the leaf of C. namaquensis. ep. = epidermis; me. = mucilage 
cells ; M = mesophyll ; xy. = xylem ; ph. = phloem, x 20. 
Fig. 2. Transverse section of a stoma, showing a clustered crystal of calcium oxalate in the 
intercellular space ; (semi-diagrammatic) C. namaqtiensis. g.c. = guard cell ; s.c. = subsidiary cell ; 
cu. = cuticle; C.O.C. — clustered crystal of calcium oxalate; i.s. — intercellular space, x 440. 
Fig. 3. Surface section of the leaf of C. gariepina, showing a stoma, x 620. 
Fig. 4. Cortex of C. gariepina . s. — sclerenchyma ; i.c. = inner cortex ; w.s.c. = water-storing 
cell ; cp. — cellulose cells of the periderm ; s.p. = suberized cells of the periderm, x 100. 
Fig. 5. Longitudinal section of C. gariepina, to show sieve-tube's, st. = sieve-tube; sp. = sieve- 
plate on lateral wall, x 1,100. 
Fig. 6. Transverse section of C. gariepina, to show part of two annual rings, m.r. — medullary 
ray. x 440. 
Fig. 7. Water-storing cells of cortex, showing large clustered crystals of calcium oxalate in 
C. namaquensis. x 220. 
Fig. 8. Outline of stem apex of C. namaquensis. v.c. = vegetative cone ; s.l. = scale leaf ; 
s.m. = suberized mass ; p. = periderm ; pa. — parenchyma; v.s. = vascular strand, x 33. 
Fig. 9. Longitudinal section through the outer part of the cortex of C. namaquensis close behind 
the stem apex. o.c. = outer cortex; c.c. = phellogen. x no. 
Fig. 10. Transverse section through the outer part of the cortex of C. gariepina, showing a later 
stage in the development of periderm, c.s.c. = crushed suberized cells, x 147. 
Fig. 11. Transverse section through bark of an old stem of C. gariepina. x 50. 
Fig. 12. Transverse section of young stem of Portulacaria afra, showing origin of phellogen in 
the epidermis, x 440. 
Fig. 13. Transverse section of an older stem of P. afra , showing formation of periderm, 
x 44°- 
