

2 8o ANGIOSPERMAEDICOTYLEDONES 



it does not return when the pressure is removed. According to Darwin, automatic 

 self-pollination readily takes place, but is far less productive than cross-pollination. 



Visitors. Darwin in England, MacLeod in Flanders, Hermann Muller in ] 

 Westphalia, and myself in Schleswig-Holstein have observed the honey-bee. Hermann 

 Muller remarks in this connexion: 'It is characteristic of the honey-bee that it I 

 does not disdain even this flower's tiny store of honey. The whole inflorescence I 

 is pulled down by the weight of the bee, which then sucks the flower's head down- 

 wards. It visits a few flowers, at most four, on one inflorescence, and then flies away 

 to another plant of the same species. Xenogamy is thus effected to a great extent.' 



While as a rule the honey-bee has been observed as the chief pollinator, 

 Burkill (Proc. Phil. Soo, Cambridge, viii, 1894, names a hover-fly (Plaiycheirus 

 mantcaius) as the most active visitor at Scarborough, a short-tongued bee {Halictus 

 mono) and a Muscid {Scatophaga) at Cambridge. He gives the following list for 

 Scarborough (June, 1893) and Cambridge (July and August, 1893). 



A. Coleoptera. 1. Anthobium torquatum Marsh. ; 2. Ceutorhynchidius floralis 

 Payk. ; 3. Meligethes aeneus F. B. Diptera. (a) Anthomyidae : 4. Anthomyia sp.; 

 5. Caricea tigrina F. ; 6. Chortophila cinerella Fall. ; 7. C. sepitorum Meade ; 

 8. C. sp. ; 9. Homalomyia armata Mg. ; 10. Hydrotea irritans Fall. ; 11. Hylemyia 

 pullula Zell.; 12. Pogonomyia alpicola Rnd. ? {b) Bibionidae'. 13. Scatopse brevi- 

 cornis Mg. (c) Chironomidae: 14. CKironomus sp. (d) Chloropidae : 15, 16, 17. 

 Three sp. of Chlorops; 18. Oscinis sp.?, very freq. (e) Empidae: 19. Empis 

 punctata /l {/) Muscidae: 20,21. Two undetermined sp. (g) Sarcophagidae : 

 22. Sarcophaga sp., very freq. (h) Scatophagidae : 23. Scatophaga stercoraria L. 

 (i) Sepsidae : 24. Hydrellia griseola Fall. ; 25. Sepsis cynipsea L. (k) Syrphidae: 

 26. Paragus tibialis Fall.; 27. Pipizella virens F. ; 28. Platycheirus albimanus F. ; 

 29. P. manicatus Mg. ; 30. P. scutatus Mg. ; 31. Syrphus balteatus Deg. ; 32. S. 

 corollae F. ; 33. Syritta pipiens L. (/) Tabanidae: 34. Ptiolina crassicornis Pz. 

 {m) Pachinidae'. 35. Myobia inanis Fall. ; 36. Siphon a cristata F. ; 37. S. genicu- 

 lata Deg. C. Hemiptera. 38. Aphis sp. ; 39. Siphonophora artemisiae Koch. D. 

 Hymenoptera. Apidae : 40. Andrena parvula K. 5 ; 41. Apis mellifica L. $? , rare ; 

 42. Bombus hortorumZ. ; 43. Halictus minutissimus K. $ ; 44. H. morioZ*. $and J, 

 not infrequent ; 45-50. Six undetermined species. E. Lepidoptera. {a) Noctui- 

 dae: 51. Hadena fasciuncula Haw. (b) Pyralidae: 52. Crambus pratellus L. 

 (c) Tineidae: 53. Porrectaria sp. (d) Tortricidae : 54, 55. Sp. of Tortrix? F. 

 Neuroptera. 56. Thrips sp. 



Sickmann mentions the fossorial wasp Gorytes lunatus Dahlb., infrequent. 



Besides the honey-bee, Herm. Miiller observed the following. 



A. Hymenoptera. Apidae-. 1. Andrena convexiuscula K. 5, skg. ; 2. A. 

 xanthura K. 5, po-cltg. ; 3. Bombus agrorum F. 5 and 5, skg. (Strassburg) ; 4. 

 Halictus flavipes F.$, po-cltg. B. Diptera. Conoptdae: 5. Myopa buccata ., 

 skg. ; 6. M. testacea ., do. C. Lepidoptera. Rhopalocera : 7. Thecla rubi 

 L. ?, skg. 



Miiller further records three Lepidoptera, skg., for the Alps (' Alpenblumen,' 

 p. 248). 



MacLeod, in addition to Apis, observed Halictus sp. in Flanders (Bot. Jaarb. 

 Dodonaea, Ghent, vi, 1894, p. 338). H. de Vries observed Bombus terrester Z.J 

 in the Netherlands (Ned. Kruidk. Arch., Nijmegen, 2. ser., 2. deel, 1875). 



673. M. arabica All. Kirchner ('Flora v. Stuttgart,' p. 484) states that 

 the flower mechanism of this South European species agrees with that of M. sativa. 



