LEGUMINOSAE 



321 



When a bee visits the flower it settles on the alae, and these, being firmly 

 united with the carina as above described, act like the long arm of a lever and 

 cause its depression. The carina and alae return to their original position after 

 the insect visitor has departed. This is partly due to their elasticity, and partly 

 because the upper basal corners of the alae are produced into backwardly and 

 inwardly directed processes, which lie upon the upper surface of the sexual column. 

 This is also grasped by the two upper basal lobes of the carina, between which 

 only a narrow space is left. And lastly, the broad base of the vexillum curves 

 so far forwards on each side that it completely surrounds the claws of the alae 

 and carina. More than half the length of the extremely short style (only about 

 i^ mm. in length), is beset with hairs from immediately below the terminal stigma 

 downwards. These are longer and closer on the outer than on the inner side. 



A- 



Fig. 105. Vicia Cracca, L. (after Herm. Miiller). (i) Flower seen from the side (x 3I. (2) The 

 same, after removal of calyx and vexillum, seen from above (further enlarged). (3) The same, after 

 the alae also have been removed. (4) Left ala from the inside. (5) Style (still more enlarf^ed). 

 a, anterior alar process; a', corresponding carinal pit; b, posterior alar process; l/, corresponding 

 carinal depression : c, backwardly and inwardly directed alar process ; </, alar claws ; e, carinal claws ; 

 y, dilatation of the carina containing pollen ; ^, upper basal lobes of the carina ; A, nectar; 0, opening 

 through which the style passes out ; p, styiar brush ; si, stigma. 



The flowers have barely reached half their full size, when the anthers, which 

 closely surround the styiar brush, dehisce and shed their pollen among the hairs 

 of the brush, the stigma being also covered with it. When a bee visits the flower, 

 pollen adheres to its under-side and the stigma is at the same time rendered sticky 

 and receptive by rupture of its papillae. 



Visitors. — These are bees and Lepidoptera, though the latter suck nectar 

 without effecting pollination. I saw Apis, 2 Bombus, and a Zygaena on the North 

 Frisian Islands ; Bombus agrorum F., skg., at Flensburg; and, in Riigen, 2 humble- 

 bees, skg. — Bombus hortorum L., and B. sylvarum, var. albicauda Schmiedekn. 



Alfken observed the following bees at Bremen. — 



I. Anthidium manicatum Z. 5; 2. Bombus arenicola Ths. 5 and 5; 3- B. der- 

 hamellus K. 5 and 5; 4. B. distinguendus Mor. 5; 5. B. muscorum F. J; 6. B. 

 sylvarum L. 5 and 5 ; 7- Coelioxys rufescens Lep. 5, skg. ; 8. Eucera difficilis (Duf ) 

 Per. 5 ; 9. Megachile centuncularis L. J and S; 10. Podalirius borealis Mor. 5. 



Krieger saw Eucera longicornis L. (once) at Leipzig. De Vries noticed 

 numerous honey-bees, skg., in the Netherlands. Heinsius saw Zygaena filipendulae 

 L., and Lycaena icarus Rott. S in Holland. MacLeod observed 2 long-tongued 

 bees, and 2 Lepidoptera in Flanders ; a humble-bee and a Lepidopterid in the 



