954 The American Naturalist. [ November, 
BOTANY. 
The Development of the Ovule of Aster and Solidago. — 
—The following is from an unpublished paper on The Development a 
of Flower and Embryo-sac in Aster and Solidago, by Dr. George W. D 
Martin. The work was done in the botanical department of the 
Indiana University in the year 1891-2: 
A short time before the floral organs attain their maximum length 2 
there appears at the bottom of the ovarian cavity a rounded excres 
cence; this is the incipient ovule, the promise of a future seed. : 
This incipient ovule does not arise from the bottom of the ovarian 3 
cavity, but a little above the lowest point. Therefore, the ovule is not a 
the terminal structure on the floral axis, for, by careful focusing, the ; 
apex of the fascicular system is seen to end very abruptly at the bottom 
of the ovary cell. To the right and left of the axial bundle of the 
pedicel, a little below the apex, are given off fibro-vascular bundles 
which traverse both sides of the capellary leaf. It is in the region of 
one of these lateral bundles, beneath the epidermis, where arise the 
primitive cells that arch upward and give rise to the funiculus and the 
nuclear ovule. Subsequently a branch of this lateral bundle enters 
the funiculus. 
At first the ovule consists of a mass of cells, the tissue of which is 
soft and cellular, and is designated the nucleus of the ovule or the 
nucellus. By further development a large nucleated cell appears 
within this nucellar tissue, which soon divides, the apical cell of which 
becomes the mother-cell of the embryo-sac. In its early development 
the nucellar body is almost orthotropous, but by further growth it 
becomes curved (caused by a stronger growth on one side) at the 
point (base of the nucellus), where the integument originates. At 
first the integument appears as an annular ring; as growth takes place 
it forms a complete wall around the nucellus; as the wall encroaches 
upon the apical portion of the nucellus the latter becomes more and more 
curved, but does not seem to be wholly inverted until the integument 
completely surmounts it, even passing far beyond the nucellar apex- 
Thus, we have an ovule which is anatropous, having a single integu- 
ment, though very thick and forming the greater mass of the ovule 
before fertilization is accomplished, investing a small central portion, 
the nucellus ; and the latter, which consists of but one layer of cells, 7 
in turn surrounds a more central portion, the embryo-sac. Originally 
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