26
foundation for the theory propounded by Celakowsky, and adopted by Schaeffer1 and
others as to the origin of the ovule from a hypothetical tissue of foliar nature which
intervenes between the ovule and the apex of the axis. To the writer the whole hypothesis
appears unnecessary ; in Cannabis it is certainly baseless.
So far, therefore, neither the organographic considerations of B. Clarke, the organo-
genic researches of Payer, nor the subjective conceptions of Celakowsky have satisfactorily
explained the nature of the ovary and the origin of the ovule of Cannabis. To Briosi and
Tognini 2 we are indebted for a careful attempt to attack the problem from the histo-
logical side. To attain their object they studied a series of progressive horizontal
sections of the base of a female flower from the level of its insertion upwards.
In the very short pedicel are to be found four vascular traces, of which one is anterior,
one is posterior, and two are lateral (PLATE 3, figs. 1, 2). Of these the anterior—α , and the
posterior—δ, are very nearly in the plane which is common to the centre of the stipule in
whose axil the flower is situated and to the centre of the leafy axis. The anterior— α , is
the smallest of the four, the posterior— δ, the largest ; the lateral ─β, γ,are opposite each
other and of equal size but are rather nearer the anterior than the posterior trace. Rather
higher up (PLATE 3, fig.3), one finds the anterior smallest trace—α, entering the base of
the involving bract ; the three remaining traces are much as before except that the
internal lateral— γ, and the posterior— δ, now slightly approach each other. Still higher
up (PLATE 3, fig. 4), the bract is now free from the axis and the anterior trace— α,
which innerves it, has given off the two strong subhorizontal zig-zag branches already
described (PLATE 2, fig. 8). The pedicel is now assuming an oval outline as it approaches
the base of the ovary and has now only three traces, the lateral ─ β, γ, and the posterior
—
δ.
The external lateral— β, is now being pulled round towards the external end of the long
axis of the pedicel ; the internal lateral— γ , and the posterior—δ, approach the internal end.
A stage higher up shows the base of the ovary and the involving bract above the level
of the subhorizontal branches of the bract (PLATE 3, fig. 5). In the base of the ovary we
find that the external lateral trace
—
β
, gives off two subhorizontal branches which run side
by side towards the periphery at the anterior side of the ovary ; the internal lateral trace—
γ, also sends out two subhorizontal branches which run round the base of the ovary, each
of the two branches giving off a slender offset which passes backward towards the periphery
at the posterior side of the ovary, coalescing as a trace— X, before they get so far ; the
posterior trace—δ, is now closer than ever to the internal lateral trace— γ, and is enclosed
within the loop made by its external subhorizontal branch. Yet higher up and just before
the base of the ovarian chamber is reached (PLATE 3, fig. 6), we find that the two
subhorizontal branches of the external lateral trace
—
β
, run up close together as the two
juxta-posed fibro-vascular bundles of the anterior carpellary rib, to the base of the anterior
stlye ; the two subhorizontal branches of the internal trace— γ, have given off a number of
vertical traces which innerve the greater part of the carpellary wall, all of it indeed except
the narrow vertical strip next the involving bract which is innerved by the two vertical
strands into which the external lateral trace —β has been divided ; finally, the posterior
trace—δ, which began as the strongest of the four original traces, is altered by the twisting
and interweaving of its histological constituents into a small swelling opposite the centre
of the base of the posterior carpellary wall, passes from thence backward towards the
periphery of the ovary at the posterior side, becomes there closely associated with but
1Fora, lxxiii. p. 62 (1890).
2 Intorno all anatomia della Canapa,i. p. 53, t. xviii, figs. 1-7.