GERANIACEAE 227 



bend towards the middle of the flower, so that the pollen-covered anthers lie above 

 them. It follows that automatic self-pollination is effected by the fall of pollen, 

 should insect-visits fail. Even after the anthers have dropped off, the stigmas remain 

 receptive. 



Visitors. — Hermann IMuller observed only a few Syrphidae. 



572. G. Robertianum L. (Sprengel, 'Entd. Geh.,' p. 337; Herm. Miiller, 

 'Fertilisation,' pp. 156-7, ' Weit. Beob.,' II, p. 218 ; MacLeod, Bot. Jaarb. Dodonaea, 

 Ghent, vi, 1894, pp. 229-30; Kirchner, 'Flora v. Stuttgart,' pp. 340-1; Schulz, 

 ' Beitr'age,' II, pp. 57-8; Knuth, ' Bloemenbiol. Bijdragen.') — Hermann Muller 

 describes the flowers of this species as slightly protandrous. The petals are rose- 

 coloured, with three paler streaks, and their claws remain erect, so that the flower 

 does not open widel)'. The nectar collects in the slightly excavated bases of the 

 sepals, and a proboscis 7 mm. long is required to reach it. When the flower opens 

 the five inner stamens are in the middle of the flower, their anthers dehiscing at 

 a somewhat higher level than the still apposed stigmatic branches, which consequently 

 get covered with pollen. The five outer stamens are curved widely outwards. 

 While the anthers of the five inner stamens still retain pollen, the stigmatic branches 

 elongate and spread out above them. When, however, these stamens have shed 

 their pollen, the five outer ones move towards the middle of the flower, and surround 

 the styles. Insect-visits effect cross-pollination, at first owing to protandry, and later 

 on because the fully mature stigmas project above the pollen-covered anthers. Self- 

 pollination, however, is not excluded. 



According to Schulz, the hermaphrodite flowers are occasionally homogamous. 

 Besides these, unisexual ones occur, distributed gynodioeciously and gynomonoe- 

 ciously, or androdioeciously and andromonoeciously. 



Warnstorf describes the pollen-grains as large, spherical, closely tuberculated, 

 and opaque, measuring 70 fx in diameter. 



Visitors. — Hermann Miiller (H. M.), Buddeberg (Budd.), and myself (Ivn.) 

 have observed the following in Central and North Germany. — 



A. Coleoptera. {a) Staphylinidae: i. Anthobium sp. (H. M.). (li) Tele- 

 phon'dac : 2. Dasytes flavipes F., skg., and gnawing the petals. B. Diptera. {a) 

 Empidae: 3. Empis sp., vainly searching for nectar (Budd.). [h) Syrphidae : 4. Rhingia 

 rostrata Z., freq., skg. and po-dvg. (H. M., Budd.). C. Hymenoptera. Apidae : 

 5. Andrena gwynana A'. $ (Budd.); 6. Bombus agrorum /'. J, skg. (H. I\I.) ; 7. B. 

 hortorum L. t^, skg. persistently (H. IM.); 8. B. lapidarius /,., skg. (Kn.) ; 9. B. ter- 

 rester /.., do. (Kn.) ; 9. Chelostoma campanuiarum K. S, do. (Budd.) ; i o. C. nigricorne 

 Nyl. S, do. (Budd.); 11. Halictus cylindricus /'. 5, do. (H. M., Thuringia); 12. Osmia 

 adunca Pz. S, do. (Budd.); 13. O. rufaZ. 5, do. (Budd.). D. Lepidoptera. Rhu- 

 palocera : 14. Pieris napi Z., freq., skg. (H. M.). 



Krieger noticed the following Apidae at Leipzig. — i. Anthidium manicatum /,. ; 

 2. Andrena gwynana K., ist generation; 3. Coelioxys rufescens Lep.; 4. Eriades 

 nigricornis Nyl.; 5. Osmia caerulescens L. ( — 0. aenea Z.) ; 6. O. solskyi Mor. ; 

 7. Stelis phaeoptera A'. 



Hermann Muller further saw 4 humble-bees, 2 hover-flies, and 3 Lepidoptera 

 in the Alps. 



Willis observed a Syrphid (Syrphus sp., skg.), a bee (Bombus agrorum F., freq., 

 skg.), and a butterfly (Pieris napi Z., skg.), in the neighbourhood of the south coast 

 of Scotland (' Fls. and Insects in Gt. Britain,' Part I). 



Q 2 



