436 ANGIOSPERMAE—MONOCOTYLEDONES 



the room, I observed a distinct secretion of nectar in the depressions on the inner 

 sides of the petals, and could also perceive it by taste. 



The inner parts of the flower are protected from rain by its pendulous position. 

 The anthers form a downwardly directed sprinkling-cone surrounding the style. 

 They dehisce by means of a down- and inwardly directed,' lancet-shaped opening. 

 Each ends in a brush-like elongation, which is struck against by insect visitors, 

 so that some pollen falls off upon them. As the stigma projects a little beyond 

 the anthers, it is touched first, so that insect-visits effect cross-pollination. Wamstorf 

 describes the pollen-grains as dark golden-yellow in colour, ellipsoidal to nearly 

 bean-shaped, on an average 37 /i long and 25 /i broad, without visible germinating 

 processes. 



Visitors. — Sprengel observed honey-bees. In sunny weather they may be 

 seen in swarms searching for the pollen and nectar. In such weather the sepals, 

 which usually closely surround the petals, diverge so that the green nectar -guides 

 may be seen. Hermann Miiller describes in detail how the honey-bee uses one 

 of the sepals as a platform, and turns thence to the entrance of the flower. 

 When collecting pollen it inserts its head and fore- and middle-legs into the 

 flower, and clings firmly with its hind-legs to the outer side of a petal. In this 

 position it brushes against the anthers with the tarsal brushes of its fore- and 

 middle-legs, and deposits the pollen thus obtained in the collecting-baskets of 

 the hind-legs. When sucking it also generally holds fast to the perianth leaves 

 from outside with its fore- and middle-legs. 



866. Stembergia Waldst. et Kit. 



2702. S. lutea Ker-Gawl. (Kerner, ' Nat. Hist. PI.,' Eng. Ed. i, II, p. 373.) — 

 Kerner states that the flowers of this species are protogynous, so that at first 

 insect-visits are necessary for pollination. After the anthers have dehisced, insects 

 probing for the nectar found at the base of the flower first brush against the stigma 

 and dust it with foreign pollen ; on penetrating further they receive fresh pollen from 

 the anthers. The flowers close in the evening, and pollen is then deposited on the 

 inner side of the perianth leaves. This is transferred to the stigma on the following 

 evening, for the perianth lobes elongate greatly during the day, so that their pollen- 

 covered parts are then on a level with the stigma, enabling autogamy to take place. 



867. Agave L. 



2703. A. lurida Ait. (=A. Jacquiniana Schull.). (Stadler, 'Beitrage.') — 

 Stadler describes flowers of this species as markedly protandrous, so that autogamy 

 is excluded. 



Visitors. — These are Muscids. 



CXII. ORDER TACCACEAE BENTH. ET HOOK. 



868. Tacca Forst 



2704. T. cristata Knuth ( = Ataccia cristata Jack). (Delpino, 'Ult. oss.,' 

 pp. 13-16; Hildebrand, Bot. Ztg., Leipzig, xxviii, 1870, p. 589.) — In this species 



