314 THE FERTILISATION OF FLOWERS. [PART IT. 
hairs to exclude rain. The honey is accessible to short-lipped 
insects, especially as the tube widens superiorly to a diameter of 
2 mm. at the mouth, and the four (rarely five) rounded lobes of the 
corolla, of which the external is the largest, are easily thrust apart.. 
On the damp, unproductive spots where Scabiosa succisa chictms : 
grows, its blue, hemispherical heads, about 20 mm. in diameter, 
are among the most conspicuous flowers; and in sunny wena | 
until the middle of September, they are visited by very numerous 
insects, and are regularly cross-fertilised owing to their pro- 
terandrous dichogamy. When the flower opens the stamens which — 
were bent inwards in the bud straighten themselves one by one; 
then, while as yet the style scarcely extends beyond the mouth of 
the corolla (Fig. 109, 2), the anthers dehisce in succession ; only when — 
the stamens are completely withered, and the anthers, if insect-— 
visits have taken place, are shaken off (Fig. 109, 3), does the style 
attain its full length, and the stigma, a little later, becomes viscid, 
Self-fertilisation can therefore only occur exceptionally, if at this — 
time an anther, still dusted with pollen, comes by accident in contact 
with the stigma. In plants flowering in my room I have observed — 
this to take place not unfrequently, but never in the open air. 
Visitors: A. Hymenoptera—Apide: (1) Apis mellifica, L. $, s. and e.p., 
ab. ; (2) Bombus silvarum, L. 9 § ¢ (as late as Oct. 7) ; (3) B. lapidarius, L., 
% 3; (4) B. agrorum, F. § ¢ (both as late as Oct. 15, 1871) ; (5) B. senilis, 
Smith, $ ¢; (6) B. terrestris, L. 3 ¢; (7) B. pratorum, L. $; (8) B. vestalis, 
Foure. 9 ¢; B. rupestris, L. ¢ (Oct. 15, 1871), all very ab., s. ; (10) Andrena — 
Cetii, Schrank. 2, ¢.p.; (11) A. convexiuscula, K. 3; (12) Habitus rubicundus, 
Christ. ?,¢p.; (13) H. leucozonius, Schrank. ¢; (14) H. cylindricus, F. by 
all freq. B. Diptera—(a) Bombylide: (15) Exoprosopa capucina, F., ab. in’ 
July ; (b) Syrphide : (16) Helophilus pendulus, L., ab., also pairiele on the 
flowers (Sept. 4, 1870) ; (17) Eristalis arbustorum, L.; (18) E. nemorum, L. ; 4 
(19) E. tenax, 1, (beginning of November) all ab., s. and fip.; (20) E 
intricarius, . scarcer; (21) Syrphus pyrastri, L., s. and f.p. ; (22) Rhingia 
rostrata, L., s.; (c) Empide : (23) Empis livida, L., s., very ab. ; (d) Muscide : 
(24) Species of Lucilia; (25) Musea cornicina, F. C. Lepidoptera—(a) 
Tthopalocera : (26) Pieris rape, L., ab. ; (27) Satyrus Janira, L. ; (28) Polyom- 
matus Phloeas, L., very ab.; (b) Noctue: (29) Plusia gamma, L., ab.; (ce) 
Crambina : (30) Botys purpuralis, L., all s. D. Coleoptera—Chrysomelide : 
(31) Cryptocephalus sericeus, L., feeding on the organs of the flower. See also_ 
No, 590, III. 
This species, also, has been shown to include female as well as — 
hermaphrodite plants in England by Darwin (167), in France by 
Lecoq,' and in Germany by Magnus (449). 
S. atropurpurea, L., also, is gynodicecious (167). 
1 Géographie botanique, 1857, vi. 
