CARYOPHYLLEAE 



165 



The colour of the corolla varies from pure white — as in males infested by Ustilago 

 violacea — to bright violet and red violet. In Spitzbergen — as in Greenland — there 

 are male and female flowers as well as hermaphrodite ones. On a clump of the 

 plant containing the remains of several hundred female flowers of the preceding year, 

 the above-named investigators only found two ripe seed-containing fruits. In their 

 opinion the fact indicated the ineffectiveness of cross-pollination in Spitzbergen. The 

 clumps of Silene acaulis often show very beautifully the effect of direct isolation on 

 anthesis, for the southern half — exposed to the sun — presents a dense mass of expanded 

 flowers while the northern half remains more or less in bud. 



Fig. 50. 5//«w£ a<^«//j, Z.. (after Henm. Miiller). A. Flower half-way through the first (male) condi- 

 tion. B. Smaller male flower at the end of anthesis. C. Female flower, seen from above. D. The 

 same in section. E. Hermaphrodite flower at the end of the male stage. F. Pistil of the same flower. 



Visitors. — Herm. Miiller observed — in the Alps — numerous Lepidoptera — 

 28 Macro-lepidoptera, and 4 Micro-lepidoptera — as well as some bees, Muscidae, 

 Syrphidae, and anther-eating beetles. 



Frey — in the same region — saw the moth Anarta melanopa Thunb., and in 

 Switzerland the species Anarta nigrita Bsd. MacLeod observed 6 Lepidoptera, and 

 3 pollen-eating beetles in the Pyrenees. Lindman noticed a humble-bee on the 

 DovreQeld, as did Ekstam in Nova Zemlia. Schneider (TromseMus. Aarsh., 1894) 

 saw Bombus agrorum Z. and B. lapponicus L. in Arctic Norway. For Spitzbergen, 

 Ekstam (' Blutenbiol. Beob. a. Spitzbergen,' p. 24) records two cases of visits by 

 small Dipterids, and one by a spider (!), which was doubtless hunting flies. 



412. S. noctiilora L. (= Melandrium noctifloriim Fries). — The hermaphrodite 

 flowers are fragrant when they open in the evening, between seven and eight o'clock, 

 according to Kerner, though Wamstorf has seen them open as early as between five 



