226 Parkin. — The Extra-floral Nectaries of Hevea brasi liens is . 
EXPLANATION OF FIGURES IN PLATE XVI. 
Illustrating Mr. Parkin’s paper on the Extra-floral Nectaries of Hevea brasiliensis. 
Fig. i. Young shoot from adult tree bearing the immature foliage leaves on its upper part. 
Natural size, s, single non-nectariferous basal bud-scale ; ns 3 , ns 5 , ns 6 , ns 8 , represent respectively 
the 3rd, 5th, 6th, and 8th nectariferous bud-scales ; this shoot possessed eight of these structures ; 
the other four are not depicted in the drawing ; the shaded areas show the position of the nectar- 
secreting parts of the scales ; in ns 8 , the uppermost scale, this part is restricted to the apex ; 
/, lowest foliage leaf ; pn , position of the petiolar nectary ; st, stipules ; Ji , young inflorescences 
in the axils of the upper scales and lower foliage leaves ; Is, leaf-scars of previous year’s shoot. 
Fig. 2. Young shoot from adult tree with many basal bud-scales. Natural size, s, imbrication 
of non-nectariferous basal scales ; ns, length of stem bearing nine nectariferous bud-scales (the 
shoot possessed twelve altogether) ; Jl , inflorescences in the axils of the nectariferous scales ; 
/, lowest foliage leaf ; st, stipules ; Is, leaf-scars of previous year’s shoot. 
Fig. 3. Part of the upper surface of a foliage leaf. Natural size, n, twin-nectary; p, upper 
part of petiole, l, lower part of one of the three leaflets ; s, short stalk of leaflet. 
Fig. 4. Individual bud-scales from shoot represented in Fig. 1. Natural size, s, single non- 
nectariferous basal scale, a, dorsal view showing pair of stipules, b, side view ; ns x — ns 7 
(inclusive), side views of seven nectariferous bud-scales in order of succession from base 
upwards, the position of the honey-secreting tissue is indicated by shading ; ns 8 , uppermost 
nectariferous bud-scale, a, side view, b, ventral view showing three points, the vestiges of the 
three leaflets — the nectar-secreting part is restricted to the apex and is shown by the small shaded 
area in this region. 
Fig. 5. Diagram of a median transverse section of a nectariferous bud-scale. x 30. 
e, ordinary epidermis ; ne, honey-secreting epithelium on the upper surface with groove, g\ fv, ring 
of fibro-vascular bundles. 
Fig. 6. Diagram of a longitudinal section of the apical part of the uppermost nectariferous 
bud-scale ( ns s in Figs. 1 and 4) showing the restricted distribution of the glandular tissue, x 30. 
e, ordinary epidermis ; ne, honey-secreting epithelium in a position corresponding to that occupied 
by the nectary of the foliage leaf ; p, one of the three apical points — vestige of a leaflet ; h, hairs ; 
v, vascular strands. 
Fig. 7. Section of the honey-secreting epithelium of a bud-scale. x 400. e, undivided 
epithelial cell ; e x , epithelial cell divided into two daughter-cells ; e 2 , epithelial cell divided into 
three daughter-cells ; ct, the thick cuticle ; n, nuclei ; c, small cortical cells full of contents and 
without intercellular spaces. The empty areas in the figure represent cells in the section from which 
the contents had accidentally disappeared during preparation. 
