82 ANGIOSPERMAE—DICOTYLEDONES 



expression — are placed just as they would be if the two drops of nectar between 

 the pairs of long filaments did not exist. The long stamens — which project above 

 the stigma — make a quarter-turn towards the adjacent short stamens, while these are 

 on the same level as the stigma and remain facing it. In sunny weather the flowers 

 open widely, and the short stamens curve far away from the stigma : when the 

 weather is continuously wet, these stamens effect self-pollination. Insects visiting 

 the flower and trying to get at the larger drops of nectar, chiefly effect cross- 

 pollination. 



Visitors. — Hermann Muller states that — in addition to the honey-bee, also 

 observed by myself — there are the following beetles and flies. — 



A. Coleoptera. (a) NitiduUdae : i. Meligethes in large numbers, nect-skg. and 

 po-dvg. (b) CurcuUonidae: 2. Ceutorhynchus sp. {c) Scarabaeidae: 3. Phyllopertha 

 horticola Z., gnawing the flower. B. Diptera. {a) Mmcidae : 4. sp. of Anthomyia, 

 skg. ; 5. Aricia incana Wiedem., skg. ; 6. Calobata cothurnata Pz., skg. ; 7. Scatophaga 

 merdaria F., skg. (b) Syrphidae : 8. Ascia podagrica F., po-cltg. ; 9. Rhingia rostrata 

 L., freq., skg. and po-cltg. 



Leow observed the following Apidae in the Berlin Botanic Garden: i. Andrena 

 extricata Sm. 5, po-cltg. ; 2. Apis mellifica L. 5, skg. : and 3. Bombus lapidarius L. 5, 

 skg. MacLeod — in Flanders — noted 2 bees, a hover-fly, and Empidae (Bot. Jaarb. 

 Dodonaea, Ghent, vi, 1894, p. 194). 



In Dumfriesshire (Scott-Elliot, ' Flora of Dumfriesshire,' p. 10) Apis, 2 short- 

 tongued bees, 2 Muscidae, 2 hover-flies, and one of the micro-Lepidoptera have been 

 recorded. 



180. B. intermedia Bor. (Kirchner, ' Flora v. Stuttgart,' p. 288 ; MacLeod, Bot. 

 Jaarb. Dodonaea, Ghent, vi, 1894, p. 195.) — The flowers are smaller and of a brighter 

 yellow than in the last species. Their diameter is only 6 mm. The flower mechanism 

 resembles that of B. vulgaris, except that there are only four nectaries. 



53. Turritis Dill. 

 Homogamous flowers with half-concealed nectar. Four nectaries. 



181. T. glabra L. (Kirchner, 'Flora v. Stuttgart,' p. 289; Knuth, ' Bloemenbiol. 

 Bijdragen.') — -The flowers are not conspicuous, for the yellowish-white petals are 

 tolerably erect. Two of the four nectaries are situated outside the bases of the two 

 pairs of long stamens : each short stamen is upon a swelling, which is drawn out into 

 a conical process on either side. Not infrequently the four nectaries coalesce into 

 a ring. The anthers dehisce introrsely ; those of the long stamens touch the stigma 

 with their loAver ends, while those of the short stamens do so with their tips, so that 

 automatic self-pollination is inevitable. Insects probing for nectar may effect either 

 cross- or self-pollination. Wamstorf (Verh. bot. Ver., Berlin, xxxviii, 1896) describes 

 the flowers as being protogynous, the stigmatic papillae maturing even before the 

 flower is fully open, while the anthers subsequently ripen at the same level as the 

 stigma, so that autogamy is rendered possible. 



Visitors. — These are but few ; I saw at Kiel only 2 hover-flies (Rhingia rostrata 

 Z., and Syritta pipiens Z.), skg. nectar. 



