~ 
162 THE FERTILISATION OF FLOWERS. [PART III. 
parietum, L. 9; (f) Apide: (31) Halictus sexnotatus, K. 9; (32) Prosopis 
sinuata, Schenk, ?, freq. ; (33) Apis mellifica, L. § ,—all the Hymenoptera 
only sucking. See also No. 590, 1. $). 
Dictamnus, L., is visited by humble-bees, whose ventral surfaces 
come in contact with the reproductive organs of the flower. In 
the first stage the style lies hidden among the stamens, in the 
second it is bent outwards with its mature stigma (178, 360, 
p- 658). 
Correa, Sm., is proterandrous, according to Delpino (178, 
p. 170). 
Orv. CELAST'RINEL. 
85. EvonyMus EUROPA, L.—The honey is secreted by a 
fleshy disc surrounding the style, and lies in so thin a layer that 
it can only be attractive to short-lipped insects. The dull yellow 
colour of the flowers moreover excludes those insects which are 
enticed only by bright colours. Like other flowers of the same 
a 
colour, these are visited only by Diptera and Hymenoptera, and — 
especially by the former ; the flies run irregularly over the flowers, — 
attacking the honey-covered surface, now here now there, with their 
outspread ‘ end-flaps’ (abelle), and in consequence touching anthers 
and stigmas now with one part of their bodies, now with another. 
In such circumstances the flowers could only attain regular cross- 
fertilisation by separation of the sexual organs, either in time or 
space. Both separations have in fact taken place, and self- — 
fertilisation, which had become unnecessary owing to the abundant 
insect-visits, has finally become impossible. . 
The four anthers stand at a distance from the stigma upon 
stiff filaments, and dehisce directly outwards, while the stigma is — 
still immature and its lobes remain tightly closed. These only — 
separate several days later, and again close up after fertilisation. 
Thus self-fertilisation cannot take place without the aid of insects ; 
and with their aid only if the earlier days of flowering have passed — 
by without the flower being visited (cf. Delpino, 177). 
Li. europea is polygamous according to Darwin (167). 
Visitors: A. Diptera—(a) Syrphide: (1) Eristalis tenax, L. ; (2) Helo- 
philus floreus, L. ; (3) Syrphus ribesii, L. ; (4) Syritta pipiens, L. ; (5) Xantho- 
gramma citrofasciata, Deg. all sucking ; (b) Muscide: (6) Musca domestica, 
L.; (7) Calliphora vomitoria, L.; (8) Sarcophaga carnaria, L., very ab. ; 
> 
(9) Seatophaga stercoraria, L. ; (10) Lucilia cornicina, F.; (c) Bibionide : (11) 
