368 REV. GEORGE HENSLOW ON THE 
the offspring of either impregnation being identical. Hence it would seem justifiable 
to consider all the florets of such members of the Compositz as do not receive the visits 
of insects as equivalent to being self-fertilized. This is quite in keeping with Mr. 
Darwin’s observations on the fertilization of flowers by pollen taken from another flower, 
but on the same plant, in that, in the majority of instances, such impregnation does 
no good. Erigeron canadense also illustrates the wide dispersion of self-fertilizing plants 
described below ; for although its native country is North America, yet it is “ now estab- 
lished in the greatest abundance as a roadside weed in almost all temperate and hot 
countries" (Bentham). A point perhaps of some significance with reference to the style 
of the Cichoracee is, that it is not only “ uniform in the tribe, but is also precisely be 
one most general in the female florets of the Order ” (Bentham). 
Lastly, the suggestion may be made that one reason why the Composite is such a 
predominant order resides in the fact of their being capable of both intercrossing and 
self-fertilization. : | 
CAMPANULACEJE.—The genus Campanula, with the remarkable collecting-hairs on the 
style, is highly differentiated for intercrossing ; but Specularia speculum produced 
almost as many capsules when covered as uncovered (Darwin) The stigmas of this 
genus are recurved, excessively like those of the Dandelion; and as the anthers reach 
to a great height, indeed almost to the summit of the pistil, the stigmas are evidently 
easily able to secure the pollen from them. M. Brongniart says that some species of 
Prismatocarpus (included under Specularia by Benth. and Hook.), as well as some Cam- 
panule, have no corollas, which “ does not hinder them from fructifying" (quoted by 
Michalet à propos of cleistogamous flowers, in Bull. Soc. Fr. vii. 467). I need hardly say 
that the absence of petals, on the contrary, is a sure indication of their being probably 
self-fertile. 
Bpecularia perfoliata has cleistogamous flowers; for a description of them I must refer 
the reader to Mr. Darwin’s ‘Forms of Flowers,’ p. 330. Prof. Oliver says that he has 
seen flowers on Campanula colorata in an intermediate condition between cleistogamous 
and perfect, witnessing thereby to the belief that the former are degraded states of the 
latter, but yet with special adaptations to self-fertilization. 
GENTIANACEJE.— Müller has made an elaborate study of the many Alpine species of 
Gentiana, and finds that while the majority are intercrossed, yet a few are adapted for 
self-fertilization. Thus he remarks of G. nivalis :— j 
“ The flowers are much smaller than in G. verna &c. and more distant one from another. One or 
some of the anthers commonly come into contact with the margin of the stigma and effect self-fertiliza- 
tion, in case cross-fertilization by insects is wanting " (‘ Nature,’ March 29, 1877). 
G. Andrewsi, according to Mr. Meehan, “ never opens at all” in America. 
Erythrea is one of the many plants whose corollas rapidly close, and by so doing wrap 
up the stamens and pistil, thus forcing the anthers into contact with the stigma, most 
probably therefore effecting self-fertilization (Tab. XLIV. figs. 21 a, b, c). - 
CoNYOLYULACEE.— Ipomea purpurea, or Convolvulus major. This proved to be highly 
self-fertile with Mr. Darwin. The self-fertility of this, as of other plants of this Order, 
is machi facilitated z the -er withering of the S Zeen BE the ant ers 
