art im.] | THE MECHANISMS OF FLOWERS. 237 
or only a thin adherent layer of it; at least, I have never found drops 
of honey, in spite of repeated searching: The flowers, which attract 
‘notice by their large petals and their strong scent, compensate the 
“numerous insect-visitors for the want of honey by the abundance of | 
pollen which the numerous stamens supply. The ring surrounding | 
he style is of material importance ; for since the stamens, when the 
lower opens, are inclined outwards and the petals remain directed 
more or less upwards, the ring and the stigmas within it form the 
mly convenient alighting-place for insects: thus insects coming 
lusted with pollen from another flower are brought into contact 
vith the stigmas first. And this is the only character present to 
sromote cross-fertilisation, for stigmas and anthers come to maturity 
together. 
Tn long-continned dull or rainy weather, insect-visits may cease 
Imost completely; but the flowers, turning towards the sun, all 
tand more or less obliquely, so that part of the pollen falls upon 
e stigmas. 
— A. Hymenoptera—A pide : (1) Apis mellifica, L. §, ¢.p.; (3) An- 
a albicans, K. 9 ¢, ¢.p.and fip.; (3) A. fucata, Sm. 2, c.p. ; (4) Halictus 
itidus, Schenck, ?, ¢.p.; (5) Megachile circumcincta, K. 2, ¢.p. ; (6) Prosopis 
ommunis, Nyl. 9 ¢,f.p., ab. B. Diptera—Syrphide : (7) Helophilus floreus, 
1; (8) Syritta pipiens, L., ab., both fp. C. Coleoptera—(a) Nitidulide: (9) 
Meligethes, ab. ; (b) Dermestide: (10) Anthrenus pimpinelle, F.; (11) A. 
erc phulariz, L,, both ab., fp.; (¢) Malacodermata: (12) Anthocomus 
iatus, L. ; (d) Edmallicobata’: (13) Cetonia aurata, L. ; (14) Phyllopertha 
" ticola, L. (both often bite large holes in the petals, shit often even devour 
le stigmas and all the anthers) ; (e) Mordellide : (15) Mordella aculeata, L. ; 
6) Anaspis frontalis, L. ; (f) Cerambycide : (17) Rhagium inquisitor, F. ; 
18) Strangalia armata, Hbst.; (19) S. nigra, L., devouring the anthers and 
hher delicate tissues; (gy) Chrysomelide : (20) Luperus flavipes. 
Sse RTE Oy Se eg EM F- 
149. Rosa ceNnTIFoLIA, L.—In consequence of its more con- 
picuous flowers, this species is still more largely visited by insects ; 
or though I have observed it more rarely than R. canina, I have a 
mger list of its insect-visitors. 
A. ao Apide: (1) Andrena albicans, K. 2? ¢, ¢. nt and f.p., 
ery ; (2) A. pilipes, F.-9? ¢, do., scarcer ; (3) A. dorsata, K. 9°, “P> 
b. 5 ; ra alictas zonulus, Sm. 9? ; (5) H. sexstrigatus, Schenck, 9; (6) H 
xnotatus, K. 9, all three c.p.; (7) Megachile cireumcincta, K. ? ; (8) M. 
er tuncularis, L. 2, both ¢.p., ab. ; (9) Prosopis propinqua, Nyl. 2 ¢; (10) 
communis, Nyl. ? ¢, both very ab., fp. ; (b) Chryside : (12) Chrysis ignita, 
—4L.; (13) Chr. cyanea, L. ; (c) Sphegide : (14) Crabro patellatus, v.d. L.  B. 
_ Diptera—Syrphidw: (15) Brachypalpus valgus, Pz.; (16) Eristalis eneus, 
_Scop.; (17) E. nemorum, L.; (18) Chrysogaster viduata, L. ; (19) Syritta 
