Fig. 9. An anthera taken from fig. 8, and more highly magnified, to show that in this early stage
it is entirely petal-like, there being no indication of the two cells, of which the first
appearance in a somewhat more advanced stage is given at fig. 10.
11. A petal of fig. 8 more highly magnified.
12. The pistilla of fig. 8, as yet distinct, scarcely at all angular, and with no manifest cavities
; so that these two bodies may be regarded as chiefly or entirely the component parts
of the stigma.
13. Two grains of pollen taken from the pollen mass of the expanded flower of Asclepiaa
curassavica.
P late XXXIII.
Development op the Embryo in the Seeds op Conifers. See Vol. I, p. 575-6.
Fig. 1. A scale of the cone of Pinus sylvestris, with its winged seeds, one of which is abortive.
Natural size.
N.B. The remaining figures are more or less magnified.
2. An unripe seed, of which the testa, in this state cartilaginous, is cut open, partly removed
and thrown back to show the included body, which is the half-ripe original nucleus with its
sphacelated apex and the free portion of the inner coat, extending from the apex to about
one third of the length of the nucleus, below which it is intimately connected with and
inseparable from the outer coat.
3. The amnios or albumen, with the coats opened and laid back. a. The body of the albumen,
with its slightly concave upper extremity; in this stage separated from 6, the apex,
which is conical above, below cylindrical, and which was suspended from the top of thé
original nucleus.
4. A plan rather than actual representation of a longitudinal section of any one seed examined,
but the parts accurately copied from the calyptrasform membranes, the funiculi or sus-
pensors, and the nascent embryos of Pinus sylvestris.
In this stage the funiculi are distinct from the calyptaeform membranes within which
they originated.
5 is also a plan of the slightly concave apex of the amnios or albumen, with its semitransparent
points or pores circularly arranged; in this species (Pinus sylvestris) seldom exceeding five,
and not unfrequently being only four or even three.
6. One of the funiculi or suspensors, with its dilated upper extremity,'to which the lacerated
remains of a thin transparent membrane adhere; the funiculus itself ramified, each of the
two lateral branches consisting of a single elongated tube or cell terminating in a rudimentary
embryo; the trunk of the funiculus composed of several (apparently four) tubes
or cells terminated by a single embryo, which is already slightly divided, the divisions
being the commencement of its cotyledons.
7, 8. Two other funiculi belonging to the same seed less advanced, but both ramified.
DESCRIPTION OF PLATES. 13
Fig. 9- A funiculus of Pinus pinaster, with its thickened head, in which the nuclei of its component
elongated cells or tubes, and its adhering lacerated membrane, are visible. The figure is
given particularly to show that in this (the only one observed) there is no opake granular
portion of the compound funiculus ; in other words, no indication of a nascent embryo.
10. A funiculus of Pinus Aiies, Linn., with its rudimentary embryo and thickened head,
still partly inclosed in the calyptræform membrane.
PLATES XXXIV, XXXV.
(From the ‘ Linnean Transactions/ vol. xx.) See Yol. I, p. 591.
Structure of Triplosporite.
Plate XXXIV.
The figures A, B, C, and D are of the natural size.
Eig. A. A portion of the surface of the Strobilus, showing the hexagonal areolae.
B, C. Transverse sections, exhibiting different appearances of the bracteae and sporangia.
D. A vertical section of fig. A.
The remaining figures, E, P, G and H, are all more or less magnified.^
E. A transverse section of the axis.
P. A more highly magnified drawing of a portion of fig. E, to show the arrangement and
proportion of the vascular and cellular tissues.
G. A horizontal section of a sporangium, made probably near its origin.
H. A portion of the outer wall of a sporangium or bractea.
P late XXXV.
All the figures magnified.
Pig. A. A vertical section of the axis, near, but not exactly in the centre, showing the ramifications
of the central cord of the axis going to the circumference of the axis, and connected or
supported by a loose cellular tissue at a a.
B. A small portion of the axis, from which proceeds a bractea cut vertically through its centre,
showing its vascular cord, and bearing on its lower and horizontal half a vertical section
of an adnate sporangium, of which the base is cellular, rising irregularly and without
spores,— probably a rare occurrence.
C. A small portion of the axis, to show the scalariform vessels with the slightly elongated
surrounding cells.
D. A similar portion, from the central axis of the bractea of fig. B.
E. A similar portion, from the line of union between the bractea and sporangium of fig. B.