32 ANGIOSPERMAE—DICOTYLEDONES 



pollination. Should insect-visits fail, the pollen of the fading anthers may reach 

 the stigmas — which continue receptive in the oldest flowers — when the plant bends 

 before the wind. 



Visitors. — Only the following Muscidae were observed by me in the North 

 Frisian islands, and at Kiel. — i. Lucilia Caesar L.; 2. Musca corvina F. ; 3. various 

 smaller species. 



Verhoeff noticed the following in Norderney. — Diptera. {a) Dolichopidae : 

 I. Dolichopus aeneus Beg. (d) Muscidae: 2. Anthomyia sp., one S, skg.; 3. Aricia 

 dispar. Fall, one S; 4. Aricia incana Wiedem. § and S, po-dvg. ; 5. Myospila medita- 

 bunda F. one 5 ; 6. Scatophaga stercoraria Z. (<:) Syrphidae : 7. Eristalis intricarius 

 Z. one 5; 8. Platycheirus peltatus Afg. one 5; 9. Pyrophaena ocymi F. one S. 



In Dumfriesshire (Scott-Elliot, 'Flora of Dumfriesshire,' p. 4), flies {Muscidae, 

 Empidae, Dolichopidae') have been observed. 



MacLeod noticed in Flanders, — one hover-fly, and one of the Muscidae (Bot. 

 Jaarb. Dodonaea, Ghent, vi, 1894, p. 179). 



73. R. Ficaria L. (Herm. MuUer, ' Fertilisation,' p. 78, ' Weit. Beob.,' I, 

 pp. 321-2; Chatin, C-R. Acad, sci., Paris, cxviii, 1894; Kerner, 'Nat. Hist. PI.,' 

 Eng. Ed. I, II; Schulz, 'Beitrage,' II, p. 179; Knuth, ' Bloemenbiol. Bijdragen.') — 

 Hermann Miiller states that the mechanism of pollination in these golden-yellow 

 flowers — which expand in the sunshine to form a star about 20-25 mm. in diameter — 

 agrees with those of R. acris and R. auricomus. Besides homogamous or slightly 

 protandrous hermaphrodite flowers, there are also female ones. At the beginning 

 of the flowering season, flowers are frequently to be found in which the number 

 of developed petals is as low as three, or even two, but later the number increases 

 to 8-10. The size of the flowers, and the number of stamens, commonly exhibit 

 very considerable variation. 



The flowers seldom set fruits. Irmisch and Hunger saw them in shady wet 

 localities, while Kerner — on the contrary — observed here and there ripe heads ol 

 fruits in sunny places, while he found the plant sterile in shady spots, with bulbils 

 in the axils of the leaves. Warnstorf states (Verb. bot. Ver., Berlin, xxxviii, 1896) 

 that at Ruppin, where the plant grows abundantly in shady ditches under walls, 

 fruits (usually 2-3 in a head) are common, the individuals bearing them also pos- 

 sessing bulbils in their leaf-axils. 



Burkill (J. Bot., London, xxxv, 1897) rightly says that the extreme rarity 

 of fruits in Ranunculus Ficaria is a puzzle. The failure to form seeds cannot 

 be ascribed to a deficiency of insect guests, for a variety of these visit the flowers 

 in large numbers. 



Chatin asserts that the bulbil-producing form produces no seeds, because it has 

 no pollen. Miiller — on the contrary — cultivated a plant with bulbils in the leaf- 

 axils, and it produced ripe seeds capable of germinating. But this species propagates 

 vegetatively — in the large majority of cases — by means of the axillary bulbils. These 

 fall off in early summer, when all the parts of the plant above the ground die down. 



Visitors. — The following have been observed by Hermann Miiller (H. M.) 

 and myself (Kn.). — A. Coleoptera. i. Meligethes, freq., skg., po-dvg., and 

 gnawing the flower-leaves (H. M., Kn.). B. Diptera. (a) Muscidae: 2. Anthomyia 

 radicum Z., very freq. (H.M.); 3. A. sp., po-dvg. (Kn.); 4. Scatophaga merdaria F. 

 (H. M.); 5. Sepsis, freq. (H. M.). (b) Syrphidae: 6. Brachypalpus valgus /"z., po-dvg 



