364 REV. GEORGE HENSLOW ON THE 
drous. Æ. hirsutum is, I think, so also; at all events the order of developmentis —calyx, 
stamens opposite the petals, pistil, corolla, which is the usual one for intercrossing *. 
In Æ. hirsutum the whole inner surface of the lobes are stigmatiferous or papillose 
and recurved ; but in Æ. parviflorum the lobes remain erect, and are papillose only at the 
edges. Moreover, they are not elevated above the anthers, and thus this species is self: 
fertilizing. In fact I feel disposed to regard it as a degraded form of E hirsutum, 
having adapted itself to homogamy. The club-shaped stigma, characteristic of other small- 
flowered species, as E roseum and E. tetragonum, is a yet further advanced stage, in 
which the lobes are completely welded together; they are, I need hardly say, self- 
fertilizing, especially, it would seem, by the longer stamens. The order of development 
is—calyx, pistil, st. opp. sep., st. opp. pet., petals. 4 
Circea lutetiana. This species is both intercrossed as well as self-fertilizing. There — | 
is an annular disk surrounding the base of the style; but in no instance did I find any 
fluid within it in a number of plants growing, partly concealed, in a shrubbery. The 
filaments have a bend about halfway up, and the anthers. at first approximate the | 
stigma; they shed their pollen just as the corolla commences to expand.  Pollinization | 
then takes place. Subsequently the filaments diverge, and not unfrequently the style 
is carried to one side by cohesion of the pollen-grains to the stigma (a fact, I see, Müller 
has also observed), into which I have seen the tubes penetrating while the grains were 
still lodged in the anther-cells (see Tab. XLIV. figs. 17 a, b). 
Gaura parviflora is even further degraded than the 2-merous Circea; for it has no 
corolla, and is cleistogamous, in that it is self-fertilizing in bud, as I found in See 4 
growing at Kew. The order of development is—calyx, pistil, stamens. | 
GInothera biennis. In this species the style rapidly outgrows the stamens in Lett 
and is adapted for intercrossing. Late in September 1876, I found flowers not half an 
inch long with the anthers all clustered round the basal parts of the stigmas. "They 
dehisced before the corolla expanded. The stigmas were quite viscid throughout their 
whole length, and pollen-tubes were freely penetrating. In normal flowers the stigmas 
are elevated one fourth to one half inch above the anthers. Now this accidental 
condition, attributable, I presume, to the lateness of the season, was, however, exactly 
like the normal condition of another American species, (E. parviflora, in which the 
petals are not half an inch in length, the stamens are erect, and it appears to be self- 
fertilizing. May not this case, again, throw light upon the origin of some species, viz., 
that by adapting themselves to colder climates, the corolla becomes dwarfed, and 
the sexual organs mature more nearly together, and so a self-fertilizing form or =e 
is produced a 
Œ. bistorta. Tn this species the stigma is globular, the pistil does not Em? the 
stamens, but both mature together, and the plant is self-fertilizing. The globular stigma 
is here analogous to the club-shaped stigmas of Epilobium and the globular ones of homo- 
gamous Cruciferze. 
Ludwigia palustris, with the habit of Pelpis, i is, without doubt, also self-fertilizing. 
* I find Miiller has observed 26 species of insects visiting E hirsutum, and believes: self-fertilization to be ës 
sible; but he notices how E. = fertilizes itself (* Nature,’ vol. ix. ia E = 
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