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24 DR. J. D. HOOKER ON WELWITSCHIA. 
papillose, borne on a flexuous style, the other a low mamilla, in no respect resembling a 
stigma in outward appearance. Mr. Brown has shown* that this fully-formed stigma is, 
in all probability, functionless and withers away without sphacelation, but that impregna- 
tion takes place through the mamilla, which, after performing its function, becomes 
remarkably developed. 
It is difficult to regard this remarkable ovule without speculating on the possibility of 
Welwitschia being the only known representative of an existing or extinct race of plants, 
in which such a stigma-like organ was really capable of performing the function of a 
stigma; and when we see this organ occurring in a hermaphrodite flower, it is easy 
to suppose that we have in Welwitschia a transition in function, as well as in structure, 
between the gymnospermous and angiospermous Dicotyledons, and that the ideal race 
consisted of hermaphrodite-flowered plants in which the office of the stigma of the 
carpellary leaf was performed by a stigmatic dilatation of the ovular coat itself. Nor 
is it difficult to trace the successive variations from this imaginary type which, in the 
course of many generations, would result, on the one hand, in the obliteration of the 
embryo-sac and suspension of the functions of the ovule in the flowers of certain indi- 
viduals, and on the other in the obliteration of the stamens and stigmatic apex of the 
ovule in the flowers of other individuals,—the once bisexual plants thus becoming uni- 
sexual. Singularly enough, Liphedra presents one step in advance of Welwitschia, in 
the total disappearance of the ovule in its male flower, and is one step behind it in the 
retention of a functionless stigmatiform disc in its perfect ovule. © eo 
Female Cones. (Plates VII. & VIIL) _ 
The female cones are 1} to 24 inches long, tetrastichous, of a bright scarlet colour 
when fresh. They present 40 to 50 decussating pairs of scales, which are more mem- 
branous than coriaceous; the seven or eight lowest pairs are empty; and the upper- 
most six to ten pairs, in the specimens examined, contained unimpregnated flowers only. 
The two or three lowest pairs of scales are connate at the base, very small; and the 
ascend, diverge, and branch excessively towards the margin. Structurally, the scales 
consist of two layers of delicate epidermal cells, enclosing a layer of tortuous filiform 
liber-cells, which radiate outwards towards the m 
within its edge (Plate VITI. figs. 21 &22). These liber-cells are quite free, unbranched, 
it, but are far less tortuous. The vascular bundles present 
nothing remarkable. Towards the thickest part of the scale are found short spicular 
* In Bennett’s « Plant. Jay. tar.’ p. 248, Mr. Brown describes this stigma as not papillose ; but it is so represented 
in my drawings taken from the living plant. 
