152 THE FERTILISATION OF FLOWERS. [parr ut. 
cross-fertilisation, but if insect-visits have taken place to a sufficient 
extent, the pollen is wholly removed before the stigmas separate, 
and cross-fertilisation is the inevitable result of further insect- 
visits. If insects do not visit the flower at all, self-fertilisation 
always takes place, as the edges, at least, of the recurving stigmas 
come in contact with the pollen, as I have repeatedly seen in the 
case of specimens flowering in my room. 
The fertilisation of the plant is therefore provided for under all © 
possible conditions. 
I have not had a direct opportunity of observing this plant 
fertilised by insects; but in sunny weather its insect-visitors must 
be fairly numerous, for Herr Borgstette, to whom I am indebted 
also for living examples of the plant, sent me the following insects 
caught by him on its flowers at Teklenburg :— 
A. Hymenoptera—(a) Apidw : (1) Andrena fulvago, Christ. 2, with pollen 
of Geranium on its collecting-hairs ; (2) A. Gwynana, K.? ¢; (8) A. parvula, 
K.9; (4) A. dorsata, K.?; (5) Halictus cylindricus, F.? ; (6) H. maculatus, 
Sm. ?; (7) H. Smeathmanellus, K. 2 ; (8) Sphecodes gibbus, L. 9 ; (9) Osmia 
fusea, Christ. (bicolor, Schrank), 2; (10) Chelostoma nigricorne, L. 9? ; (0) 
Sphegide: (11) Ammophila sabulosa, L. ; (c) Vespide: (12) Odynerus 
(Hoplopus) quinquefasciatus, F. B. Diptera—(a) Syrphide: (13) Helo- 
philus floreus, L.} (14) Chrysotoxum bicinctum, L.; (15) Melithreptus 
teeniatus, Mgn. ; (16) M. pictus, Mgn. ; (17) Syrphus balteatus, Deg. ; (18) 
S. ribesii, L.; (19) 8. pyrastri, L.; (20) Ascia podagrica, F.; (21) Rhingia 
rostrata, L. ; (22) Pelecotoma tricincta, Men. ; (b) Muscide: (23) Echinomyia 
fera, L.; (24) Scatophaga stercoraria, L. C. Coleoptera—(a) Dermestide : 
(25) Byturus fumatus, L. ; (6) Cistelide: (26) Cistela murina, L.; (e) 
Malacodermata : (27) Malachius eneus, L. 
On the Alps I found G. pyrenaicum abundantly visited by 
insects, and incapable of spontaneous self-fertilisation (609). The 
stamens bent far outwards before their anthers withered, and the 
stigmas did not expand until all the anthers or at least the outer 
five had fallen off. 
79, GERANIUM SANGUINEUM, L., in spite of its flowers being 
much more conspicuous, agrees fully i in the manner of its fortilieat 
tion with G. pyrenaicum ; its conspicuousness seems therefore not 
to insure cross-fertilisation in any greater degree but only to 
compensate for its more shady habitat. 
Visitors: A. Hymenoptera—(a) Apidae: (1) Halictus maculatus, Sm. 9 ; 
(2) H. sexnotatus, K, ? (both usually alight on a petal, and go round 
the flower, licking one nectary after another—their sides rub against. the 
anthers in young flowers and the stigmas in old ones,—sometimes they alight 
bt 
ae pe ee, Smo CO TS me Pi we 
