LABIA TAE 289 



Galeobdolon Z.). (Herm. Miiller, 'Fertilisation,' p. 496, ' Alpenblumen,' p. 311, 

 ' Weit. Beob.,' Ill, p. 48 ; Kirchner, ' Flora v. Stuttgart,' p. 623 ; Schulz, ' Beitrage/ II, 

 p. 221 ; MacLeod, Bot. Jaarb. Dodonaea, Ghent, v, 1893, p. 368; Knuth, 'Bloemen- 

 biol. Bijdragen.') The mechanism of the yellow flowers of this species agrees essen- 

 tially with that of L. album. The corolla-tube is 8 mm. long, but broad enough to 

 enable a bee with a proboscis 6 mm. long (and therefore the honey-bee) to reach the 

 base of the flower. The upper lip again corresponds exactly to the shape of the bee 

 or humble-bee's body. At the beginning of anthesis the tip of the downwardly- 

 directed stigmatic branch is situated slightly above the lower surface of the anthers. 

 It is therefore not touched when a humble-bee merely brushes the anthers lightly with 

 its back : when a large one, however, presses the anthers more strongly upwards, its 

 tip is struck, but not on the same spot as the anthers. Cross-pollination consequently 

 takes place more easily than self-pollination. Later on the tip of the stigmatic branch 

 protrudes downwards between the anthers, so that it comes into contact with visitors 

 before they brush against these, and cross-pollination is effected. Should insect-visits 

 fail, automatic self-pollination generally takes place, pollen falling naturally on to the 

 lower stigmatic branch. Warnstorf describes the pollen-grains as pale yellow in 

 colour, ellipsoidal, delicately tuberculate, about 37 /^ long and 27 /x broad. 



Visitors. Herm, Miiller (H. M.) and Buddeberg (Budd.) give the following 

 list. 



A. Diptera. Syrphidae: i. Rhingia rostrata Z., skg. (Budd.). B. Hymeno- 

 ptera. Apidae: 2. Anthophora personata ///. $, skg. (H. M., Strassburg) ; 3. Apis 

 mellifica Z. 5, on one occasion skg. legitimately, but generally stealing nectar through 

 holes made by Bombus terrester; 4. Bombus agrorum F. 5, very numerous, skg. 

 legitimately, and brushing pollen from above into its collecting-baskets ; 5. B. hor- 

 torum Z. 5, do. (H. M.); 6. B. pratorum Z. 5 and 5, do. (H. M.); 7. B. rajellus 

 K. $, not so frequent, do. (H. M.) ; 8. B. sylvarum Z. 5, do. (H. M.) ; 9. B. 

 terrester Z. 5, perforating the flowers, though able to suck legitimately (H. M.); lo. 

 Xylocopa violacea Z. $ (H. M., Strassburg). 



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



Knuth (Schleswig-Holstein), 3 humble-bees at the same time i. B. agrorum F. 5, 

 skg. legitimately; 2. B. hortorum Z. 5, do.; 3. B. terrester Z. 5, perforating the 

 flowers and stealing nectar. Schulz, flowers perforated by humble-bees. Wiistnei 

 (Alsen), the humble-bee Bombus agrorum F., skg. Alfken (Bremen), 7 bees i. Apis 

 mellifica Z. 5> skg. ; 2. Bombus agrorum F. 5, very common, skg. and po-cltg. ; 

 3. B. derhamellus K. 5 and 5, do. ; 4. B. jonellus K. j and 5, do. ; 5. B. hortorum 

 Z. J, skg. ; 6. B. lapidarius Z. 5, do. ; 7. B. muscorum F. 5, do, Herm. Miiller 

 (Alps), 2 humble-bees. MacLeod (Flanders), 3 humble-bees (Bot. Jaarb. Dodonaea, 

 Ghent, v, 1893, p. 368). Loew (Berlin Botanic Garden), the honey-bee, vainly skg., 

 its head and thorax dusted with pollen. 



723. Moluccella L. 



Flower mechanism as in Lamium. The calyx is modified into an extremely 

 large protecting roof. 



2321. M. laevis L. (Knuth, Bot. Centralbl., Cassel, Ixxii, 1897.) This Syrian 

 species bears homogamous humble-bee flowers. The mechanism of those cultivated 

 in the Kiel Botanic Garden closely agrees with Lamium, but differs from all our 

 native Labiatae in the excessive development of the calyx. This forms a slightly 



