rarvun}| ‘HE MECHANISMS OF FLOWERS. 151 
(Thur.) ; (4) Stelis aterrima, Pz. 2? ¢ (Thur.), s. ; (5) Andrena Coitana, K. ¢ 
_ (Sid.), 9 (Thur.), s.; (6) Halictus cylindricus, F. ¢; (7) H. albipes, F. ¢; 
(8) H. leucozonius, K. ? ; (9) H. longulus, Sm. ¢; (10) H. maculatus, Sm. ¢ 
_ (Thur.),—all sucking ; (11) H. lucidulus, Schenck, ?, c.p.; (12) Prosopis 
hyalinata, Sm. ¢,s. B, Diptera—Syrphidq: (13) Melithreptus pictus, Mgn., f.p. 
_ See also No. 590, It. 
78, GERANIUM PYRENAICUM, L.—The flowers are _proter- 
androus, and regulariy fertilise themselves in default of insect- 
visits. Before the bud expands, all the filaments have their thin 
ends bent slightly outwards. 
As soon as the flower opens, the five outer stamens, which 
alternate with the petals and which bear at their base the honey- 
glands, rise up so that their anthers overtop the divisions of: 
em an arms 
A\ UM) iY) y 
ia 
"4 
; Fic. 46.—Geranium pyrenaicum, L. 
F 1-4.—Positions of the reproductive organs at successive stages. 
the stigma, which are still closely united, and each anther turns 
that side where dehiscence is about to take place outwards and 
upwards: this whole surface becomes covered with pollen. At the 
_ same time the thin ends of the five inner stamens curve down- 
_ wards, so that their anthers which are still closed are out of the 
' way of insects, and do not hinder them from dusting themselves 
with pollen. A day later these five inner stamens rise up and 
] dehisce, so that now the stigmas are surrounded by a circle of ten 
_ anthers, all dusted on their outer sides with pollen. 
H ' After a day or two more, the stigmas at last begin to separate 
} i from one another, and when they do so, they lie on a level with 
| the anthers. If the pollen has not in the meanwhile been removed, 
| an insect-visitor may now accomplish self-fertilisation as easily as 
i 
