PART III. | THE MECHANISMS OF FLOWERS. 77 
pumila, Gyll.; (e) Cidemeride: (30) Cidemera virescens, L., ab.; (/) 
Cistelide: (31) Cistela murina, L., devouring the petals and stamens ; 
(g) Cerambycidw : (32) Strangalia nigra, L., do.; (hk) Chrysomelide: (33) 
Helodes aucta, F., devouring the petals, along with its larvee (May 24, 1870) ; 
(34) Cryptocephalus sericeus, L., devouring the anthers. C. Hymenoptera,—(a) 
Tenthredinide : (35) Cephus spinipes, Pz., ab., s. and devouring the anthers ; 
(36) Cephus, small undetermined species; (b) Sphegide: (87) Oxybelus 
_ uniglumis, L. ; (c) Vespide: (88) Odynerus spinipes, H. Sch. 2 (quinque- 
fasciatus, F.) ; (a) Apide : (39) Prosopis hyalinata, Sm. ¢, s. and f.p.; (40) 
 Halictus longulus, Sm. ?, s.; (41) H. flavipes, F.?, c.p. ; (42) H. villosulus, 
_ K. 9; (43) H. sexsignatus, Schenck, ?, s.; (44) H. rubicundus, Chr. ?, s. ; (45) 
_ H. quadricinctus, F.?, cp. ; (46) H. leucozonius, Schr. 9, laden with poilen, 
sheltering itself from the rain in flowers of R. bulbosus (June 10, 1871) ; 
(47) H. zonulus, Sm. ¢,s.; (48) H. cylindricus, F. 2, e¢.p.; (49) H. maculatus 
 Sm.? ¢,s. and «p.,ab.; (50) H. nitidiusculns, K.?,s.; (51) H. sexnotatus, 
_K.9,cp. and s.; (52) Andrena fulvicrus, K.? ¢, s. and c.p., ab.; (53) A. 
albicans, K. 9 ¢, do.; (54) A. albicrus, K.¢,s.; (55) Panurgus calcaratus 
_ Scop.,.s.; (56) Chelostoma florisomne, L. 2? ¢, cp. and s.; (57) Osmia 
rufa, L.¢, s.; (58) Apis mellifica, L. $, s. D. Lepidoptera—(59) Lyczna 
icarus, Rott. ; (60) Satyrus pamphilus, L. ; (61) Polyommatus Phloeas, L.; (62) 
Euclidia glyphica, L., alls. See also No. 590, 1., pp. 49—59 ; No. 609, p. 135. 
If we compare the insect-visitors of these species of Ranunculus 
with those of the typical Umbelliferze, we observe the following 
remarkable differences. (1) Since the honey lies less exposed, 
_ those insects which are least fitted for sucking flowers are ab- 
sent, viz. Neuroptera, Ichneumonide, Tipulidae, etc.; Sphegide and 
Vespide are only met with sparingly. (2) Of the flies, Syrphida 
_ form the great majority; they are fond of brilliant colours, and 
are attracted by the bright yellow of the Ranunculus flowers, 
(This love of colours is clearly expressed in their own colours, the 
_ result of sexual selection.) (3) It is also owing to their bright 
colour that the flowers are frequented by the beetle Cryptocephalus 
sericeus, and that Anthaxia nitidula resorts to them for pairing. 
In these and in many other beetles, as in the humble-bees, it 
seems as if the habit of feeding on flowers had called out the 
colour-sense and the taste for bright colours, and that sexual 
selection had then been guided by this taste. (4) Bees occur 
much more abundantly on flowers of Ranunculus than on the 
Umbelliferze, because the former .are richer in both honey and 
pollen. These flowers seem especially to meet the wants of the 
genus Halictus, of which I have taken twelve species on them, 
mostly in abundance. Besides the least specialised bees (Drosopis, 
Halictus, Andrena) and the most specialised (Apis), intermediate 
genera, such as Panurgus and Chelostoma, which are absent from 
Umbellifera:, visit the flowers of Ranunculus. 
