BORAGINEAE 125 



of the peduncle, so that the stigma is brought into the line of fall of the pollen, when 

 autogamy results. 



A proboscis of at least 1 1 mm. in length is required to reach the nectar hy 

 probing between the anthers, but one of 8 mm. would be able to get at it between 

 the filaments. As already explained, however, the latter way is barred by means of 

 hollow scales, the edges of which are beset with minute prickles. Insects with 

 a proboscis less than 1 1 mm. long can therefore only secure the nectar by perforating 

 the corolla, This is done extremely often by three kinds of humble-bee, i.e. Bombus 

 terrester L. g (j)roboscis 7-9 mm.), B. pratorum L. 5 (prob. 8-9 mm.), and B. lapi- 

 darius L. ^ (prob. 9-10 mm.). The honey-bee also sucks nectar through the holes 

 thus made, but Loew says that but little harm is done to the flowers in this way. 

 WarnstorfF describes the pollen-grains as white in colour, ellipsoidal, smooth, on an 

 average 33 yw. long and 27 ^ broad. 



Visitors. — Herm. Miiller gives the following hst, in which only those insects 

 indicated by an asterisk (*) suck legitimately and effect pollination. — 



A. Coleoptera. N itiduUdae : I. Meligethes. B. Diptera. Syrphidae: 2. 

 *Rhingia rostralaZ., skg. C. Hymenoptera. Apidae: 3. *Anthophora personala 

 ///., skg. ; 4. *A. pilipes F. ^\ 5. Apis mellifica L. 5, carefully examining the bases 

 of the flowers, but not perforating them ; only skg. through holes (made by Bombus 

 terrester) already present (Westphalia and Strasburg) ; 6. Bombus agrorum F.<^ and 5. 

 very common, skg. legitimately (Westphalia and Strasburg) ; 7. B. lapidarius L. 5. 

 perforating the narrow part of the corolla-tube from outside ; 8. B. pratorum T.. 5, 

 do. ; 9. *B. rajellus K. 5 and 5 ; 10. *B. sylvarum L. 5 and 5 ; 11. B. terrester L. §, 

 as 7 (Westphalia and Strasburg); 12. Eucera longicornis L. S, creeping right into the 

 flowers; 13. Halictus sexnotatus K. 5, skg. through holes made by humble-bees; 

 14. *Osmia aenea L. 5, skg. (Strasburg); 15. *Xylocopa violacea L. j and S, skg. 

 (Strasburg). 



Loew observed the following bees in the Berlin Botanic Garden. — 



I. Anthidium manicatum L., using holes made by humble-bees; 2. Andrena 

 nitida Fourcr. 5, po-cltg. ; 3. Anthophora pilipes F. 5, skg. ; 4. Apis mellifica Z. 5, skg. 

 through holes made by humble-bees ; 5. Bombus agrorum F. 5, skg. ; 6. B. hortorum 

 L. 5, skg. legitimately; 7. B. hypnorum L. 5, skg.; 8. B. lapidarius L. 5, do., and 

 perforating the flowers; 9. B. terrester L. 5, perforating the flowers; 10. Halictus 

 sexnotatus K. 5, creeping into the flowers and trying to suck. Also in the var. 

 coccineum Hort. — 11. Bombus pratorum L. 5, vainly skg. 



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



Knuth (Kiel), the following 7 bees, skg. legitimately — i. Bombus agrorum F. j ; 

 2. B. hortorum Z. 5 ; 3- B. lapidarius Z. 5 ; 4. B. rajellus K. 5, as a nectar-thiel ; 

 5. Apis mellifica Z. 5 ", 6. Bombus lapidarius 5 ; 7- B. terrester Z. 5. von Frickeu 

 (Westphalia and East Prussia), the Nitidulid beetle Meligethes symphyti Heer. 

 Alfken (Bremen), 5 bees — i. Bombus agrorum F.'i^; 2. B. arenicola Ths. 5 ; 3. B. 

 derhamellus K. '<!^; 4. B. lucorum Z. 5 ; 5. B. ruderatus F. 5, skg. Krieger 

 (Leipzig), the bee Eucera longicornis Z. S. MacLeod (Flanders), 8 humble-bees, 

 2 bees (Eucera sp.; and Apis, stealing nectar), a hover -fly, and a Lepidopterid (Bot. 

 ]aarb. Dodonaea, Ghent, v, 1893, p. 333). H. de Vries (Netherlands), 3 humble- 

 bees — I. Bombus agrorum Z". 5 ; 2. B. hypnorum Z. 5; 3- B. pratorum Z., var. 

 subinterruptus K. 5 (Ned. Kruidk. Arch., Nijmegen, 2. Ser., 2. Deel, 1875). ScotL- 

 Elliot (Dumfriesshire), 3 humble-bees (' Flora of Dumfriesshire,' p. 123). 



1975. S. cordatum Waldst. et Kit. (Loew, ' Bliitenbiol. Floristik,' p. 280.)— 

 This Hungarian species bears yellowish-white flowers, which are shorter than thotc 



