98 ANGIOSPERMAEDICOTYLEDONES 



MacLeod saw in Flanders, 6 long-tongued and 8 short-tongued bees, 8 hover- 

 flies, 2 Muscidae, 3 Lepidoptera, and a beetle (Bot. Jaarb. Dodonaea, Ghent, vi, 1894, 

 p. 204). 



Schletterer noted two bees at Pola, 1. Halictus calceatus Scop. ; 2. H. fasciatellus 

 Schenck. 



Cobelli (Verh. ZoolBot. Ges., Wien, xl, 1890) observed on the flowers of the 

 variety sabauda, 50 Apidae belonging to the genera Andrena, Anthophora, Apis, 

 Bombus, Chalcidoma, Chelostoma, Eucera, Halictus, Melecta, Nomada, Osmia, and 

 Xylocopa ; while the later-flowering variety botryiis-asparagoides was visited only by 

 eleven species of Apidae, which were also less numerously represented. 



230. B. Rapa L. (Kirchner, 'Flora v. Stuttgart,' p. 298 ; Schulz, ' Beitrage,' I, 

 pp. 3-4; MacLeod, Bot. Jaarb. Dodonaea, Ghent, vi, 1894, pp. 204-5; Knuth, 

 'Bl. u. Insekt. a. d. nordfr. Ins.,' pp. 27-8.) The golden-yellow, slightly protogynous 

 flowers agree with the last species as regards the number and position of the nectaries, 

 but Kirchner says that the actively secreting ones on the inner side of the short 

 stamens are divided into two tubercles. When the flowers open the anthers are 

 still unripe, and those of the four long stamens lie close to the already mature 

 stigma. Before the corolla has fully expanded the anthers dehisce, and at the same 

 time the filaments make a half-turn so that their pollen-covered sides are directed 

 outwards. Schulz states that in some cases they make only a quarter-turn. The 

 anthers of the short stamens remain with their pollen-covered sides turned towards 

 the stigma, but they are 2-3^ mm. below it. When the flower fades, the long 

 stamens which project somewhat beyond the stigma curve a little, so that auto- 

 matic self-pollination may take place, and according to Kirchner and Hildebrand 

 (' Die Geschlechtsvert. b. d. Pfl.,' p. 70), this is effective, though Lund and Kjaerskou 

 ('Morph. Beskriv. af B. oleracea &c.'), as well as Focke, describe the plant as 

 self-sterile. Insects visiting the flowers will, as in the last species, chiefly effect 

 cross-pollination, which results in the production of many seeds. 



Visitors. Besides the honey-bee (skg. and po-cltg.), I have observed the 

 following at Kiel: po-dvg. hover-flies (Helophilus pendulus Z., Syritta, Eristalis 

 tenax Z., E. nemorum L., Syrphus), and also the useless guest Meligethes. 



Krieger noticed Prosopis communis Nyl. at Leipzig. 



Schmiedeknecht observed the following Apidae in Thuringia. 1. Andrena 

 flessae Pz. ; 2. A. floricola Ev. ; 3. A. dorsata K. ; 4. Osmia bicolor Schr. $> ; 

 5. O. rufa Z. ; and according to Piccioli mentions 6. Andrena florentina Magr., 

 for Florence. 



Schenck noticed the following Apidae in Nassau. 



1. Andrena albicans Mull.; 2. A. chrysosceles K. ; 3. A. cineraria Z. ; 4. A. 

 combinata Chr. ; 5. A. convexiuscula K. ; 6. A. extricata Sm. ; 7. A. flavipes F. ; 

 8. A. floricola Ev. ; 9. A. gwynana K. ; 10. A. parvula K. ; 1 1. A. propinqua Schenck ; 

 1 2. A. punctulata Schenck ; 1 3. A. nitida Fourcr. ; 14. A. trimmerana K.\ 15. Halictus 

 albipesZ 7 . ; 16. H. interruptus Pz. 5 ; 17. Nomada alternata K. ; 18. N. succincta 

 Pz. ; 19. N. xanthosticta K.\ 20. Osmia bicolor Schr. 



231. B. Napus L. (Herm. Miiller, ' Weit. Beob.,' II, p. 204 ; Kirchner, ' Flora v. 

 Stuttgart,' p. 299 ; Knuth, ' Bl. u. Insekt. a. d. nordfr. Ins.,' p. 28.) The mechanism 

 of the golden-yellow slightly protogynous flowers entirely agrees with that of the last 



