320 THE FERTILISATION OF FLOWERS. [parr m1. 
hairs, project beyond it, and diverge so widely that insect-visitors 
come in contact with them all round, and carry off upon their 
hairy or scaly coats the pollen that had been entangled in the — 
hairs of the styles. Afterwards, the lower stigmatic portions _ 
emerge from the anther-cylinder and from the throat of the 
corolla (Fig. 110, 2), and they too diverge so widely that an insect — 
in obtaining its honey must come in contact with them. Cross- — 
fertilisation is thus ensured, if insect-visits have taken place to a — 
sufficient extent to clear all the pollen from the hairs of the style — 
before the stigmas in the same floret are exposed. But if these _ 
hairs still bear pollen when the stigma becomes exposed, an insect- 
visitor may effect self-fertilisation as easily as cross-fertilisation. — 
If no insects visit the flower at all, fertilisation and even cross- — 
fertilisation are still possible, for the outspread branches of the | 
style sometimes come in contact with the stigmas of neighbouring 
florets. 
Visitors: A. Hymenoptera—Apidw: (1) Apis mellifica, L. $, s.; (2) 
Bombus (Apathus) inane: Foure. g, 8. 2 Diptera—(a) Syrphide: (3) 
Eristalis arbustorum, L.; (4) E. nemorum, L.; (5) E. tenax, L., all three ~ 
species, ab., f.p.; (6) Muscide : (6) Echinomyia fera, L. ;: (7) tera canina, — 
F.; (8). Lucilia albiceps, Mgn. C. Lepidéptera——Riopalodara® (9) Pieris” 
rape, L.; (10) Thecla quercus, L.; (11) Lyczena, sp. ; (12) Vanessa Io, L., ab. ; 
(13) Argynnis Paphia, L., ab.; (14) Satyrus Galatea, L.; (15) 8. Medusa, S. ~ 
V.; (16) S. Egeria, L.; (17) Hesperia lineola, O. I saw all these butterflies 
together sucking the flowers of Eupatorium on a sunny slope near Willebadessen 
(August, 1871) : they took no heed of other neighbouring flowers. D. Neuro- 
ptera—(18) Panorpa communis, L. This list is very remarkable on account 
of the preponderance of butterflies. See also No. 590, rt. 
Tribe Asteroidee. 
215. SOLIDAGO VIRGA-AUREA, L.—In the florets of the disk 
the style is identical with that of Chrysocoma (cf. Hildebrand, 357). 
But while in Chrysocoma numerous capitula unite to form one 
surface, and can therefore dispense with ligulate marginal florets, 
in S. virga-aurea the capitula are distributed over an elongated 
axis; and the disk of each capitulum (4 to 5 mm. in diameter) is 
rendered conspicuous by five to seven golden-yellow marginal 
florets which increase the whole diameter of the capitulum to 14 or 
even 19mm. The marginal florets have acquired their excessive 
development of corolla at the expense of their stamens, which are 
quite absent ; the branches of the style have almost entirely lost — 
their useless sveening saa and bear stigmatic papille along thee 
whole length of both borders of their inner surfaces. | 
(ban... < aed ds. Dib ty Supine 
4 
