264 ANGIOSPERMAE—DICOTYLEDONES 



I. Apis mellifica L. ^ (H. M., A., Kn.); 2. Bombus agrorum F. 5, infrequent 

 (A., Kn.); 3. B. distinguendus Mor. 5, freq. (A.); 4. B. lapidarius Z. 5 (H. M., V., 

 Kn.); 5. B. hortorum Z. (A., Kn.); 6. B. muscorum F. 5, freq. (A.); 7. B. terrester 

 Z. 5 (H. M., v., Kn.) ; 8. Eucera longicornis Z. S (L.). 



H. de Vries saw the honey-bee in the Netherlands, and MacLeod noticed Apis, 

 3 humble-bees, 3 Andrenae, and 3 hover-flies in Flanders. In Dumfriesshire, Apis, 

 a humble-bee, and several Diptera have been recorded (Scott-Elliot, ' Flora of 

 Dumfriesshire,' p. 42). In England Saunders observed Eucera longicornis Z. with 

 its parasite Nomada sexfasciata Pz. 



As unbidden guests, Hermann Miiller observed bees (Andrena fulvicrus K. 5, 

 Halictus zonulus Sm. 5, Osmia fusca Chr. 5), hover-flies (Rhingia rostrata Z.), and 

 beetles (Anthobium abdominale Gr., A. florale Gr., and Meligethes). In Wiesbaden 

 Rossler noticed moths - — Trifurcula immundella Z., Fidonia famula Esp., and 

 Threnodes pollinalis Schiff. In Westphalia and East Prussia von Fricken saw 

 the Curculionids Bruchus villosus F. and Tychius venustus F. destroying the flowers, 

 and the Chrysomelids Cryptocephalus vittatus F. and Gonioctena olivacea Forst., 

 po-dvg. 



194. Spartium L. 



640. S. junceum L. — There is an explosive mechanism in this species. 

 Visitors. — Delpino (' Ult. oss.,' I) more particularly noticed the carpenter bee, 



Xylocopa violacea Z. At Pola Schletterer observed 3 bees — i. Andrena flavipes /'s., 

 2. A. mono Bi-ulL, and 3. the mason bee Megachile muraria Z., the last as 'one 

 of the few nectar-loving guests.' 



195. Genista L. 



Yellow, homogamous, nectarless bee flowers ; with an explosive mechanism. 

 The stamens and pistil come into contact with the ventral surface of the visiting 

 bees. Only one effective visit is possible. More rarely there is a simple valvular 

 arrangement. 



641. G. tinctoria L. (G. Henslow, J. Linn. Soc. Bot., London, x, 1869; 

 Herm. Miiller, 'Fertilisation,' pp. 188-92, ' Weit. Beob.,' II, p. 257; MacLeod, Bot. 

 Jaarb. Dodonaea, Ghent, vi, 1894, pp. 332-3; Knuth, ' Bl. u. Insekt. a. d. nordfr. 

 Ins.,' pp. 56-7, 152, 'Weit. Beob. U. Bl. u. Insekt. a. d. nordfr. Ins.,' p. 232.) — 

 The yellow flowers of this species are associated in racemes, and devoid of nectar 

 and nectar-guides. The two pentamerous whorls of stamens, and the projecting 

 style, are closely surrounded by the carina. The anthers of the four upper stamens 

 of the outer whorl dehisce in the bud, discharging their pollen into the carina, 

 while their filaments shrivel. This pollen remains lying above the style, and is 

 pushed into the tip of the still growing carina by the elongation of the five inner 

 stamens. Shortly before the vexillum unfolds the pollen of the six undehisced stamens 

 is discharged, so that now the upper part of the carina closely surrounds all the pollen, 

 and the lower part the style. The latter and the staminal tube together make up 

 a stretched spring exerting an upward pressure, while the claws of the carinal 

 petals and the interlocked alae constitute a second spring which presses downwards. 

 These opposing forces are in equilibrium, and the parts concerned remain horizontal, 



