8 



ANGIOSPERMAE—DICOTYLEDONES 



possibly skg. nectar. D. Lepidoptera. Rhopalocera : 5. Rhodocera rhamni Z. 

 (H. M.), settling: for a considerable time and probing various parts of the base of 

 the flowers with the tip of its extended proboscis ; 6. Vanessa urticae Z. (Kn.), 

 possibly skg. nectar. 



14. H. angulosa DC. — 



Loew observed on the flowers in the Botanic Garden at Berlin. — Hymeno- 

 ptera. Apidae: Apis mellifica Z. 5, po-clig. 



5. Pulsatilla Tourn. 



Protogynous flowers with concealed honey (rarely pollen flowers). Nectar 

 secreted by external vestigial stamens. The large brightly-coloured sepals serve 

 for attraction. In addition to the hermaphrodite flowers, some species (P. vulgaris, 

 vernalis, pratensis, and montana) possess others which are andromonoecious and 

 androdioecious, gynomonoecious, and gynodioecious. 



15. P. vulgaris Miller (= Anemone Pulsatilla Z.). (Sprengel, 'Entd. Geh.,' 

 p. 290; Herm. Muller, 'Weit. Beob.,' I, pp. 313-14; Schulz, ' Beitrage,' I, p. 2; 

 Knuth, ' Bl. u. Insek. a. d. nordfr. Ins.,' pp. 17, 147, ' Bloemenbiol. Bijdragen.') — 



Fig. 3. Piilsaiilla vulgaris^ L. (from nature), l. Flower from which the two anterior sepals have 

 been removed. 77, nectaries. The numerous stigmas project beyond the anthers. 2. Stigma \s) of a central 

 carpel. 3- Stigma (^) of a marginal carpel. {2 and 3 highly magnified. 1 



The large blue-violet sepals form an effective means of attraction to the erect flowers. 

 In the first flowering-stage the stigmas are already receptive, and they remain in this 

 condition for the next two to four days, while the extremely numerous stamens are 

 dehiscing. Nectar — as in the case of the following species — is secreted by the outer- 

 most stamens, which are converted into stalked capitate structures. As the stigmas 

 project far above the longest stamens (see Fig. 3, i), pollen-collecting and nectar- 

 sucking insects first come into contact with them, and effect cross-pollination if they 

 have already visited a flower of the same species. 



Visitors. — Hermann Muller (H. M.) and myself (Kn.) have chiefly observed 

 nectar-sucking and pollen-collecting bees as pollinators, and ants as nectar-thieves. — 

 A. Hymenoptera. (a) Apidae: i. Apis mellifica L. 5, skg. and po-cltg. (Kn., 

 freq. atKiel; H.M., Thuringia); 2. Bombus lapidarius Z. $, skg. (Kn., Kiel; H. M., 

 Thuringia); 3. B. terrester Z. 5, skg., holding on by stamens and peduncles during 

 the process, and working round the flower to empty the nectaries in succession (Kn., 



