196 ANCIOSPERMAE—DICOTYLEDONES 



autogamy is easy, while insect visitors effect cross- and self-pollination with equal 

 facility. 



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

 stated. — 



Herm. Miiller (Lippstadt), 5 small nect-skg. bees — i. Andrena cingulata F. 5; 

 2. Halictus albipes F. ^\ 3. H. punctatissimus Schenck j ; 4. H. zonulus Sm. 5 ; 

 5. Sphecodes gibbus L. 5 and 4. Schletterer (Pola), 2 bees — i. Halictus calceatus 

 Scop.; 2. H. malachurus K. 



2127. V. peregrina L. (Kirchner, 'Flora v. Stuttgart,' p. 591.) — The small 

 white flowers of this species are devoid of nectar-guides, and generally pseudo- 

 cleistogamous. Even in sunny weather they only open occasionally, and then do 

 not fully expand, for the four lancet-shaped equal corolla-lobes are directed vertically 

 upwards, making a little bell of which the opening is scarcely i mm. wide. They are 

 homogamous, and possess neither nectar nor nectar-cover. The style is so short that 

 the stigma is almost sessile, and placed below the two anthers. Automatic self- 

 pollination is inevitable, and as numerous fruits are set is undoubtedly effective. 



2128. V. vema L. — 



Visitors. — Schletterer (Tyrol) saw the bee Eriades florisomnis L. 



2129. V. triphyllos L. (Herm. Muller, 'Weit. Beob.,' Ill, p. 35; Kirchner, 

 ' Flora V. Stuttgart,' p. 590.) — The flowers of this species are homogamous, deep-blue 

 in colour, streaked with darker lines and possessing a white or yellowish centre, but 

 only a feebly developed nectar-cover. The white filaments are not thin at their 

 bases, and the blue anthers are at the same level as the stigma, so that automatic 

 self-pollination is inevitable when the flower closes, as it does in the afternoon and 

 during dull weather. Insect visitors effect cross- or self-pollination irregularly. 



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

 stated. — 



Herm. Miiller (Thuringia), 2 bees — Andrena gwynana K. 5, skg., and Apis 

 mellifica L. 5, po-cltg., and (?) skg. Alfken (Bremen), the bee Halictus morio 

 F. J, skg. 



2130. V. agrestis L. (Herm. Muller, ' Weit. Beob.,' Ill, pp. 33-5 ; Kirchner, 

 ' Flora V. Stuttgart,' p. 593.) — The mechanism of this species is essentially the same 

 as that of V. Chamaedrys, but is incompletely developed. The scattered homo- 

 Ljamous flowers are considerably smaller and therefore less conspicuous, so that 

 automatic pollination often takes place as a last resort. The milk-white corolla has 

 a bluish tinge, and is marked with convergent lines serving as nectar-guides. The 

 nectary, nectar-reservoir, and nectar-cover are as in V. Chamaedrys. The style and 

 stamens project straight out of the flower for the same distance; the latter are 

 somewhat attenuated at the base and curve somewhat outwards. During dull weather 

 the flowers open less widely, so that the anthers and stigma are in contact, automatic 

 self-pollination being thus brought about, and this is undoubtedly effective. 



Visitors. — Herm. Miiller observed the following in Thuringia. — 



A. Diptera. Muscidae: i. Anthomyia sp., skg. B. Hymenoptera. Apidae: 

 2. Andrena parvula A'., skg. and po-cltg.; 3. Apis mellifica L. 5, po-cltg.; 4. Bombus 

 agrorum F. 5, skg. for a short time. 



