LABI AT AE 



305 



' Bliitenbiol. Floristik/ pp. 39 1, 394, 399; Knuth, 'Bliitenbiol. Herbstbeob.,' ' Bliitenbiol. 

 Beob. a. d. Ins.Rugen.') The dirty-red flowers of this species possess a nectar-guide on 

 the lower lip in the form of white lines pointing towards the corolla-tube. As in 

 most labiate flowers, the lower lip forms a convenient alighting-platform, and its 

 lateral lobes act as holdfasts for their fore- and middle-legs : a longitudinal furrow 

 on the lower lip serves as a guide to the proboscis. The nectar, secreted by the base 

 of the ovary, is concealed at the bottom of the corolla-tube, which is 7 mm. long, and 

 slightly widened at the top. It is accessible to a proboscis 6 mm. long, as the 

 widening of the entrance permits the insertion of a bee's head to a depth of one mm. 

 A circlet of stiff" hairs situated above the nectar is described by Sprengel as a nectar- 

 cover. This is, however, unnecessary, owing to the 

 horizontal position of the flower and the arching of 

 the upper lip. Hermann Miiller considers the circlet 

 as a protection against useless nectar-seeking flies, as 

 it prevents their broad proboscides from entering, 

 though it is no obstacle to those of bees. 



At the beginning of anthesis the stigmatic 

 branches, still almost apposed, are situated behind the 

 anthers. When these have dehisced, the style bends 

 downwards, the papillose stigmatic branches diverging 

 at the same time, so that they are first brushed against 

 by a bee visitor. If the pollen is not removed by 

 insects, a large part of it clings to the hairy margins 

 of the upper lip, and the whole length (including the 

 papillae) of the lower stigmatic branch, which bends 

 down between the hairs, is dusted with the retained pollen, so that automatic self- 

 pollination is effected. 



Schulz says that besides hermaphrodite flowers, gynomonoeciously distributed 

 female ones also occur (often up to 15 %). Gynodioecism is rare. 



Visitors. Loew observed the following bees. Mecklenburg (M.) and Branden- 

 burg (B.) (' Beitrage,' p. 43). 



1. Anthidium manicatum Z. $ and $, skg., $ also po-cltg. (M.); 2. Anthophora 

 furcata Pz. J, skg. (M.) ; 3. A. quadrimaculata F. 5, do. (B.) ; 4. Bombus agrorum 

 F. t, do. (B.); 5. B. sylvarum L. J (B.); 6. Tetralonia salicariae Lep. $, do. (B.): 

 Silesia (op. cit., p. 34), Saropoda rotundata Pz. 5, skg. 



Schenck saw the following 8 bees in Nassau. 



I. Anthidium manicatum Z. ; 2. Biastes emarginatus 6V^ff^ ; 3. Bombus 

 agrorum F. ; 4. Epeoloides caecutiens F. ; 5. Halictus clypearis Schenck, 5 freq., 

 J once ; 6. Podalirius furcatus Pz. ; 7. P. retusus Z. ; 8. P. vulpinus Pz. 



Burkill and Willis observed the following at Cambridge (' Fls. and Insects in 

 Gt. Britain,' Part i). 



A. Diptera. Syrphtdae: i. Rhingia rostrata Z., skg; 2. Syritta pipiens 

 Z., do. ; 3. Syrphus sp., do. B. Hymenoptera. Apidae: all skg. : 4. Bombus 

 agrorum F.; 5. B. cognatus Steph.; 6. B. latreillellus Kirby\ 7. Halictus sp. 

 C. Lepidoptera. (a) Noctuidae: 8. Plusia gamma Z., skg. (<5) Rhopahcera : 

 9. Pieris rapae Z., skg. 



Fig. 338. Ballota nigra, L. (after 

 Herm. Muller). (i) Reproductive or- 

 gans of a young flower, seen obliquely 

 from the front (X 7). (2) Do. of an 

 older flower. (3) Ovary [pv) and 

 nectary (w). 



