324 ANGIOSPERMAEDICOTYLEDONES 



(2) The style does not grow quite so fast as the corolla and stamens ; it 

 projects, therefore, at the most only half as far beyond the corolla at the 

 end of anthesis as at the beginning. 

 II. The style elongates during anthesis much less rapidly than corolla and 

 stamens, or even does not grow at all, so that the stigma comes into contact 

 with the anthers, 

 (i) Corolla and stamens elongate little or somewhat slowly, so that the stigma 

 only touches the anthers after it has shrivelled. Cross-pollination is 

 necessary in this case also, and automatic self-pollination excluded. 

 {2) Corolla and stamens elongate so quickly and to such an extent that 

 stigma and anthers touch soon after dehiscence of the latter. Automatic 

 self-pollination is therefore possible. There is often scarcely any secre- 

 tion of nectar. 



B. The style does not protrude from the bud. The stigma, which is receptive 



before dehiscence of the anthers, either touches them or stands close in front 



of them at the beginning of anthesis. Automatic self-pollination is therefore 



inevitable. There is often scarcely any secretion of nectar. 



The first three forms of Schulz correspond, therefore, to Miiller's first, and his 



two last to Miiller's second stage. 



I was only able to distinguish two forms of the variety litoralis Fries 

 {= E. verna Bell.), which is found everywhere in the North Frisian Islands. These 

 two forms agree essentially with those of Miiller. One of them is adapted exclu- 

 sively for cross-pollination, but the other is capable of automatic self-pollination. 



The flower mechanism of the above-named variety completely agrees with that 

 of the main type in other respects. 



Visitors. Alfken observed the following bees, all skg. 



Juist Bombus muscorum F. 5, 5 and J, very common, skg. Bremen 

 I. Bombus arenicola Ths. 5 and J ; 2. B. lapidarius Z. 5 and $; 3. B. muscorum F. 

 5, 5 and J; 4. B. sylvarum Z. 5 and S; 5. B, terrester Z. 5 and 5; 6. B. variabilis 

 Schmiedekn. 5 and S. 



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



Knuth (Schieswig-Holstein), the honey-bee and 2 humble-bees Bombus 

 agrorum F., and B. lapidarius Z.; all skg. Herm. Miiller, the honey-bee (skg., 

 sometimes above and sometimes below the stamens ; also breaking into unopened 

 flowers with projecting styles) and 2 humble-bees, skg, Bombus lapidarius Z. j and 

 5, and B. sylvarum Z. 5 and J. Loew (Mecklenburg), the humble-bee B. sylvarum 

 Z. 5, skg. and po-cltg. (' Beitrage,' p. 43). Friese (Mecklenburg, teste Brauns), the 

 bee Andrena denticulata K., rare : (Alsace, Fiume, Mecklenburg, Thuringia, Saxony, 

 and Hungary), the bee Melitta melanura Nyl. von Dalla Torre (Tyrol), the humble- 

 bee Bombus muscorum F. S. Schletterer (Tyrol), the humble-bee B. variabilis 

 Schmiedekn. H. de Vries (Netherlands), the humble-bee B. subterraneus Z. 5 (Ned. 

 Kruidk. Arch., Nijmegen, 2 Sen, 2 Deel, 1875). MacLeod (Flanders), the honey- 

 bee, 4 humble-bees (almost exclusively 5), and a hover-fly (Bot. Jaarb. Dodonaea, 

 Ghent, v, 1893, pp. 350-2). Scott-Elliott (Dumfriesshire), a humble-bee ('Flora of 

 Dumfriesshire,' p. 132). 



2173. E. officinalis L. (Sprengel, 'Entd. Geh.,' p. 315; Herm. Miiller, 

 'Fertilisation,' pp. 447-50, ' Alpenblumen,' p. 279, *Weit. Beob.,' Ill, p. 35; 



