GENTIANEAE loi 



aromatic, directed obliquely or vertically upwards, externally bright or dark purple in 

 colour, and of whitish-yellow towards their bases both externally and internally. 

 Longitudinal green veins on the inner surface serve as nectar-guides. The club- 

 shaped corolla is thrown into internal longitudinal folds, and its length is 35 mm., 

 of which 10 mm. are taken up by the six lobes. The filaments are free down to the 

 place where the corolla narrows, but below this are fused with the longitudinal folds, 

 to constitute high ridges extending to the ovary and leaving five narrow tubular 

 nectar-passages. There are six green nectaries at the base of the ovary, between 

 the bases of the filaments. The anthers are completely fused together and dehisce 

 extrorsely. They surround the style, and the two stigmas project beyond them 

 and mature somewhat earlier. Although the stigmas roll up later on into spirals 

 of more than one turn, they do not come into contact with the anthers, and 

 automatic self-pollination does not therefore take place. 



Visitors. — The size and structure of the flowers would indicate humble- 

 bees as the pollinators, but Kirchner never saw them at Zermatt, though he 

 observed numerous flies, which flew about inside the blossoms, and occasionally 

 touched the anthers and stigmas. 



1897. G. pannonica Scop. — Kerner describes this species as protandrous. 



1898. G. cruciata L. — Kerner says that the protandrous flowers of this species 

 open 8-9 a.m. and close again 7-8 p.m. 



Visitors. — Schulz observed flowers perforated by humble-bees in Central 

 Germany. 



1899. G. asclepiadea L. (Herm. MuUer, ' Alpenblumen,' pp. 356-7; 

 Delpino, 'Ult. oss.,' pp. 166-7; Hildebrand, Bot. Ztg., Leipzig, xxviii, 1870, 

 pp. 668-9.) — This species bears protandrous humble-bee flowers, in which 

 automatic self-pollination is generally excluded. Hermann Miiller did not observe 

 the true pollinators, but only Bombus mastrucatus perforating the flowers, and 

 stealing the nectar. He convinced himself that the opening of the flowers is 

 not dependent upon the action of light, but of warmth, for he picked a bunch 

 of closed flowers and placed them in a dark, but warm room, where they began 

 to open in 25 minutes. Kerner, on the contrary, believes that opening (which 

 takes place 8-9 a. m.) is brought about by the stimulus of light. According to 

 him self-pollination takes place when the corolla closes, in the same way as in 

 the next species. 



Visitors. — Vide supra. Hoff'er (Steiermark) observed 2 humble-bees — Bombus 

 gerstaeckeri Mor. $, po-cltg., and B. latreillellus K. 5, skg. 



1900. G. Pneumonanthe L. (Sprengel, 'Entd. Geh.,' pp. 150-2 ; Warming, 

 ' Arkt. Vaxt. Biol.,' p. 10; Herm. Miiller, ' Fertilisation,' pp. 403-4; Schulz, ' Beitrage '; 

 MacLeod, Bot. Jaarb. Dodonaea, Ghent, v, 1893, pp. 381-2 ; Kirchner, 'Flora v. 

 Stuttgart,' p. 540; Kerner, 'Nat. Hist. PI.,' Eng. Ed. i, II, p. 373; Knuth, 'Bl. u. 

 Insekt. a. d. nordfr. Ins.,' p. 105, ' Weit. Beob. ii. Bl. u. Insekt. a. d. nordfr. Ins.,' 

 p. 238.) — This species bears protandrous humble-bee flowers. The large deep-blue 

 corolla is marked externally with five green streaks, and is 30 mm. long with an 

 entrance 8-io mm. broad. Nectar is secreted by the base of the ovary, and is 



