654 ANGIOSPERMAE—DICOTYLEDONES 



In the first stage of anthesis the florets are covered by an abundance of bluish- 

 coloured pollen; in the second stage the stylar branches diverge somewhat at the 

 tip, and their papillose stigmatic edges swell outwards. The second stage lasts 

 considerably longer than the first. Should insect-visits fail, automatic self-pollination 

 may be effected by the further swelling of the stigmatic margins of the stylar branches, 

 until they touch the pollen that remains clinging to the floret. But autogamy is 

 scarcely likely to take place, for Hermann Miiller observed a very large number 

 of insect visitors (not less than 103 species) in Switzerland, i.e. 8 beetles, 10 flies, 

 31 Hymenoptera, and 54 Lepidoptera. 



Visitors. — Loew observed the humble-bee Bombus terrester Z. S, skg. in the 

 Berlin Botanic Garden, and the following in Switzerland (' Beitrage,' p. 58). — 



A. Diptera. (a) Bomhyliidae : i. Argyromoeba sinuata Fall, skg. (3) Empidae: 

 2. Empis tessellata F. (c) Tabanidae: 3. Tabanus bromius L. B. Hymenoptera. 

 Apidae : 4. Halictus quadricinctus F. '^•, 5. Osmia villosa Schenck 5 and S, skg., 

 $ also po-cltg. C. Lepidoptera. {a) Rhopalocera : 6. Parnassius delius Esp. 

 (b) Sphingidae : 7. Zygaena exulans Hchw. et. Rein. 



1543. C. Personata Jacq. (= Arctium Personata Z.). (Herm. MuUer, 'Alpen- 

 blumen,' pp. 417-18.) — In this species there are about 6 burr-like purple-red heads 

 at the end of the stem, each measuring 30-40 mm. in diameter. Each of the 150-200 

 florets in a head possesses a corolla-tube 7-9 mm. in length, and a bell (ventricose 

 below) about 3 mm. long. The filaments are highly irritable. In other respects the 

 flower mechanism agrees entirely with that of C. defloratus, the filaments of which, 

 however, are less or not at all irritable. 



Visitors. — Herm. Miiller noticed 2 beetles, 6 flies, 3 humble-bees, and 6 

 Lepidoptera. 



Loew observed 2 bees in the Berlin Botanic Garden — i. Apis mellifica Z. 5. 

 skg. ; 2. Osmia fulviventris Pz. 5, po-cltg. 



1544. C. nutans L. (Sprengel, 'Entd. Geh,,' pp. 370-1; Herm. Miiller, 

 'Fertilisation,' p. 340, ' Weit. Beob.,' Ill, pp. 83-4; Loew, ' Bliitenbiol. Floristik,' 

 p. 390 ; Kirchner, ' Flora v. Stuttgart,' p. 390,) — Kirchner says that in this species 

 several hundred purple-red florets are aggregated into an odorous head, which 

 presents a surface about 40 mm. in diameter. The corolla-tube of each floret 

 is 10 mm. and the bell 5 mm. long, while the corolla-lobes vary from 5 to 8 mm. in 

 length. In other respects the flower mechanism agrees with that of C. arvense. 



Visitors. — Herm. Miiller gives the following list for Central Germany. — 



A. Diptera. Syrphidae: i. Eristalis tenax Z., po-dvg. ; 2. Syrphus ribesii Z., 

 do. B. Hymenoptera. Apidae : 3. Apis mellifica Z., freq., skg. ; 4. Bombus 

 hortorum Z. S, skg. ; 5. B. hypnorum Z. g, do. ; 6. B. pratorum Z. 5 and S, do. ; 

 7. B. sylvarum Z. 5 and 9, do.; 8. Psithyrus vestalis Fourcr., do.; 9. Halictus 

 cylindricus F. $, do.; 10. H. leucozonius Schr. 5, po-cltg. ; 11. H. malachurus K. 5, 

 skg. ; 12. H. quadrinotatus K. S, do. (Thuringia); 13. H. sexcinctus F. 5, skg. and 

 po-dvg.; 14. H. zonulus Sm. 5, skg. (Thuringia). C. Lepidoptera. (a) Rhopa- 

 locera: 15. Argynnis aglaja Z., in large numbers, skg. ; 16. A. paphia Z., skg. ; 17. 

 Epinephele janira Z., do. (Thuringia); 18. Hesperia hneola O., skg. (3) Sphingidae : 

 19. Zygaena lonicerae Esp., skg. 



The following were recorded by the observers, and for the localities stated. — 



