424 BOTANICAL GAZETTE [JUNE 
EXPLANATION OF PLATES. 
PLATE XXII, 
The figures, with the exception of figs. 75, 76, 77, are diagrams. In all 
others, unless otherwise indicated, the optical combination was Reichert ocular 
4 and Bausch and Lomb +}; oil immersion. The drawings have been reduced 
to three-eighths of their original size as drawn with the Zeiss camera. 
Fic. 1. Young bud of a cyathium of £. coro//ata with no differentiation 
of flowers. 
Fig. 2. Same older, showing developing involucre (7) in axils of bracts 
(6). Vascular bundles in this and succeeding figures indicated by dotted 
lines. 
Fic. 3. Still more advanced stage, in which five staminate flowers (s*) 
have developed in the axils of the involucral leaves; the free margin of the 
papilla is slightly elevated into three ovules. Two cyathia of a younger 
generation are shown in the axils of the bracts (4). 
F1G. 4. Ovules more advanced (0). Carpels have appeared at the bases 
of the ovules (c). A second group of staminate flowers, each of which isa 
branch from the staminate flower just above it (s*). Involucre enclosing all 
flowers. 
Fic. 5. Carpels about to unite with axis of flower. A mature staminate 
flower (st) with a notch marking the insertion of the filament upon the 
pedicel. Staminate flowers of the second, third, and fourth generations 
showing the dichasial arrangement. The gland (g) and ingrowing flap are 
developing on the inner margin of the involucre, while the five free petal- 
like parts are turning outward. In this, as in the preceding figures, 4 indi- 
cates the two green leaves which envelop the cyathium. 
F1Gs. 6—10 show the shifting position of the ovule from nearly erect to an 
anatropous suspended position. The two integuments are shown in each 
figure, the inner appearing the earlier. 
Fic. 11. The nearly mature ovule with the nucellar neck bent toward the 
glandular hairs on the placenta. The shape of the embryo sac and the pad 
of thick walled small cells at the base of the nucellus are shown diagram- 
matically. 
Fic. 12. Habit sketch of a cyathium after fertilization of ovules. A 
younger cyathium is developing in the axil of one of the green bracts that 
enveloped the older cyathium during its growth. 
FiG. 13. Ground plan of cyathium. 
Fic. 14. Diagram of main inflorescence, a cymose umbel. 
Fig. 15. Portion of an abnormal cyathium in which no pistillate flower has 
developed. 
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