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ON THE SEXUAL ORGANS OP THE CYCADACEiE.
By F. a. W. Miquel.
Translated hy W. Thiseltox Dyde, B.A.
(Plates XCI. and XCII.)
{Concluded.)
The suspensors spring from the base of the corpuscles. They are
more or less spirally twisted, and descend at first to penetrate into
the central cavity of the endosperm, but afterwards they are more or
less pushed upwards by the embryo. I have not succeeded in ascer-
taining if the suspensors of neighbouring corpuscles can coalesce with
one another. It often happens that only one suspensor is well de-
veloped, and this produces the embryo. This is shown in Plate XCII.
fig. 2 and 4-, where the suspensor proceeds from a corpuscle which
appears lacerated, or has been destroyed in making the section. Its
remains are still visible at the base of the sterile corpuscles. In fig. 8
however, there are two twisted slispensors, the longest of them bearing
the embryo. The suspensors produce lateral branches which terminate
in rudimentary embryos in the form of tubercles (fig. 4 and 8).
These filamentary bodies represent the structure which the older car-
pologists called the flum suspensorium, and which E. Brown called
the suspensor. T have proposed for it, in consideration of its function,
the name embryoblastanon. Others had applied the ievm proerabryo to
it. In no other group of plants is this structure so complex as in
Cycads. It is more or less cylindrical in shape, and composed of an
aggregation of numerous elongated cells (Plate XCII. fig. 7). The
remains of a delicate membrane may be distinguished on its surface
I am not able to give any explanation of it, but it may possibly be
caused, like the membrane on the surface of the embr^-o, by a slight
adhesion to the eudospermic tissue. Such an adhesion might easily
take place between the superficial cells of organs which are in contact
during the time of their growth. '
The consistence of the filament is
firm and solid. It is only at the point of junction with the embryo
that it breaks readily.
The endosperm, in the axis of which the embryo is tightly packed,
is entirely unattached in the cavity which it occupies (Plate XCI. fig.
17 ; Plate XCII. fig. 11-13). At its surface the appearance of the
VOL. VII. [APRIL 1, 18G9.] H
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