ROSACEAE 393 



12. Even in varieties which are fertile with their own pollen that of other 

 varieties is more efficient, and when crossing is not prevented by the exclusion of 

 insects most of the fruits seem to result from it. 



13. Typical fruits, and, as a rule, the largest and best examples from all the 

 varieties, are the result of crossing, whether the varieties are self-sterile or self-fertile. 



Waite extended his experiments to apples and quinces. The varieties of the 

 former exhibit even a greater tendency towards infertility when dusted with their 

 own pollen than is the case with pears. The quince, on the other hand, is almost 

 equally fertile with self- and cross-pollination. 



Visitors. Herm. Muller (H. M.) in Westphalia, and myself (Kn.) in Schleswig- 

 Holstein, observed the following. 



A. Coleoptera. (a) Coccinellidae'. 1. Coccinella conglobata Z., nect-lkg. 

 (H. M.). (b) Curculionidae: 2. Rhynchites aequatus Z., nect-lkg. (H. M.). (c) Niti- 

 dulidae : 3. Meligethes, freq. (H. M.). (d) Phalcridae: 4. Olibrus aeneus F, nect-lkg. 

 (H. M.). B. Diptera. (a) Muscidae : 5. Anthomyia radicum Z. J and <j>, very freq., 

 skg. (H. M.) ; 6. A. sp. (Kn.) ; 7. Calliphora erythrocephala Mg., skg. (H. M.) ; 

 8. Lucilia cornicina F., do. (H. M., Kn.) ; 9. Musca corvina F., do. (H. M.); 10. M. 

 domestica Z., do. (H. M., Kn.); n. Pollenia rudis F., do. (H.M.); 12. P. vespillo 

 F., do. (H. M.) ; 13. Sarcophaga carnaria Z. (Kn.); 14. Scatophaga merdaria F., skg. 

 and po-dvg. (H. M.) ; 15. Sepsis sp., skg. (H. M.). (6) Syrphidae : 16. Ascia poda- 

 grica F., freq., skg. and po-dvg. (H. M.); 17. Eristalis arbustorum Z., skg. and 

 po-dvg. (H. M.) ; 18. E. intricarius Z., do. (H. M.) ; 19. E. nemorum Z., freq., do. 

 (H. M.); 20. E. tenax Z., do. (H. M., Kn.); 21. Melanostoma mellina Z., skg. and 

 po-dvg. (H. M.); 22. Rhingia rostrata Z., do. (Kn.); 23. Syritta pipiens Z., do. 

 (H. M., Kn.). C. Hymenoptera. (a) Aptdae: 24. Andrena albicans Mull. $ and 

 $, freq., skg. and po-cltg. (H. M., Kn.); 25. A. collinsonana K. $, do. (H. M.) ; 

 26. A. gwynana K. 5, do. (H. M., Kn.); 27. A. parvula K. $, do. (H. M., Kn.); 

 28. Apis mellifica Z. jf, do. (H. M., Kn.); 29. Bombus terrester Z. 5, skg. (H. M.); 

 30. Halictus rubicundus Chr. 5, skg. and po-cltg. (H. M.). (5) Formicidae : 31. Lasius 

 niger Z. 5, nect-lkg. (H. M.). (c) Tenthredinidae : 32. Dolerus gonager F., occasional, 

 skg. (H. M.); 33. Nematus capraeae Z. (=Nematus gallicola Sleph.-F.), in large 

 numbers, skg. (H. M.). D. Thysanoptera. 34. Thrips, freq. (H. M.). 



Alfken noticed the following bees at Bremen: 1. Andrena nigroaenea K. t>; 

 2. A. varians K. 5 ; 3. Bombus agrorum F.$; 4. B. lucorum Z. $. 



934. P. salicifolia L. (Kirchner, 'Beitrage/ p. 38.) This oriental species 

 was studied by Kirchner in the Hohenheim Botanic Garden. He found its flowers 

 to be protogynous, and to agree in other respects with those of P. communis. 



267. Sorbus L. 



Flowers white or rose-red in colour, and aggregated into dense panicles; 

 homogamous, protogynous, or protandrous; with half-concealed nectar secreted 

 a ring at the base of the style. 



935. S. Aucuparia L. (Herm. Muller, 'Fertilisation,' pp. 239-40; Warnstorf, 

 Schr. natw. Ver., Wernigerode, xi, 1896.) Hermann Muller describes the flowers 

 of this species as protogynous, agreeing as regards their mechanism with those of 

 Crataegus Oxyacantha, which they also resemble in odour (that of trimethylamide). 

 As many flowers are aggregated into large conspicuous inflorescences, insect visitors 



