8 
POPULAR SCIENCE REVIEW. 
monia , spread them out on first opening, but bend them in 
again subsequently ; while in others, though the outermost 
stamens may mature before the carpels, yet the inner will 
mature together with them, so that both intercrossing and self- 
fertilisation are possible. 
OnagracejE. — j Epilobium angustifolium and hirsutum are 
proterandrous, but the small-flowered species scarcely open their 
blossoms at all, and the pollen-tubes may be easily seen pene- 
trating the stigmas from the grains within the anther-cells, 
which thus become “ glued ” to the stigmas. Figs. 34 and 35 
represent the stamens and pistil of Circcea lutetiana. On first 
expanding, the anthers are close to the stigma, but they after- 
wards spread away as if adapting themselves for insect fertilisa- 
tion. The stigma, however, has often become pollinated early, 
and is thus dragged to the side by sticking to the anther. 
Composite. — Contrary to the general opinion, many of this 
order appear to be constantly self-fertilised. Fig. 36 shows how 
the stigmatic branches in the Cichoracece become strongly 
recurved so as to penetrate amongst the pollen-grains. Inde- 
pendently of that, however, some of the grains mostly fall into 
the “ cleft.” In Groundsel the stigmatic arms are often 
retained below, but separate, within the anther-tube, and so 
self-fertilisation is secured. Indeed the heads of this order con- 
stitute a sure way of securing seed, for the .florets can impreg- 
nate one another, which is quite equivalent to self-fertilisation. 
Labiate. — This order, with its highly differentiated corolla, is 
obviously adapted to be intercrossed, but it has, like most, if 
not all others, self-fertilising species. Thus Lamium amplexi- 
caule has cleistogamous flowers (fig. 37-39) ; while Salvia 
clandestina has its stigmas recurved between the anthers (figs. 
40-42). Prunella (fig. 43) is also often self-fertilising.* 
ScrophulariacetE furnishes several self-fertilisers, though of 
course, as in the Labiatse, the great variations in the corollas are 
so many special adaptations to insects. Some genera, like 
Euphrasia and Rhinanthus , are dimorphic : one form with a 
larger corolla has the stigma thrust forward as in fig. 44, but 
the other and smaller flower has the stigma strongly recurved so 
as to reach the anthers (fig. 45). The common garden Calceo- 
laria (fig. 46) is quite self-fertile, the stigma being in close 
conjunction with the anthers ; but there are several species, 
such as C. glutinosa and Pavonia , forming the section 
“ Aposecos ” (see “ Genera Plantarum,” sub nom.), which have 
the anthers disjoined with a long connective between them, so 
that they oscillate exactly like the anthers of the genus Salvia. 
Primulace^e. — The genus Primula has several species di- 
For descriptions, see below, p. 14. 
