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Ig00] LIFE HISTORY OF SILPHIUM 103 
dependent upon the age of the bud and the exact portion of 
these folds appearing in the section. This infolded portion 
finally unrolls to form the limb of the corolla. 
Although the stamens never reach maturity in the ray flow- 
ers, they are to be found in the great majority of young flowers. 
While one may be in doubt as to their identity in fig. 73, con- 
clusive proof of their presence is found in jigs. 14,15, 16. Fig. 
20 shows a single anterior stamen in median section, whereas 
figs. 18, 19, of almost the same age, show no such rudiment, 
even in lateral sections. The significance of this last statement 
is seen upon an examination of jig. 21, in which only the two 
carpels (£) appear in a median section, while, in a lateral section 
g. 21, a), two stamen rudiments (s¢) are found. In one head, 
two flowers were found, each showing a single stamen which 
had developed to the pollen-mother cell stage (fig. 24). 
The Ovary arises as a cavity below the carpels, soon widen- 
ing at the base as the ovule becomes visible. The Anlage of the 
ovule appears slightly toward the posterior side of the base of the 
ovary (figs. 75, 16), grows obliquely upward (figs. 78, 79), and 
soon becomes erect (figs. 20, 27). In the last figure cited, the 
apex of the nucellus is already pushed slightly to one side, 
but hardly enough to warrant the statement of Sachs (14, p. 572) 
that the nucellus, when first visible, stands laterally below the 
apex of the funiculus, a mode of development for some anatrop- 
ous ovules first described by Cramer (zézd.), and later called in 
question, at least for Compositae, by Kohne (2b:d.). It seems 
plain that in a stage just earlier than that of fig. 27, perhaps in 
jig. 20, the cell which later becomes recognizable as the arche- 
Sporium occupies an exactly terminal position upon the young 
ovule; and the bulging on the anterior side, already begun 
in fig. 27, is merely the beginning of the integument, which, 
growing from now on more rapidly than the nucellus, forces the 
latter to a lateral position, and finally completely inverts it 
(figs. 22-25). 
The often affirmed lateral origin of the ovule is thrown in 
doubt by the fact that Martin (19) relates it by its bundle, 
