Night-fiowering Silenecs. 131 



have made the subject of special investigation, viz., 

 SUme pwmdoxa L., 8. longiflora Ehrh., 8. ciliata 

 Pourr., 8. vallesia L., 8. sax'ij'raga L., 8. Kitodhelii 

 Vis., and 8. nutans. 



In all these plants each flower lasts, unless exposed 

 to any unusual disturbance, three days and three nights. 

 On the first day, when the perianth has opened late in 

 the afternoon, the anthers of those five stamens which 

 are opposite to the sepals come forward, so as to be 

 visible at the mouth of the corolla between the claws 

 of the petals, their loculi, however, being as yet closed. 

 Their filaments now lengthen very rapidly, occupying 

 from one to two hours in the process ; and by the time 

 the sun has gone down and twilight set in, the five 

 anthers on their straight stiff filaments are seen to stand 

 more or less in adva];ice of the aperture, the loculi to 

 have opened, and the whole anther to be covered with 

 poUen. This condition lasts till the forenoon of the 

 following, that is of the second, day. The stamens then 

 bend outwards, and the anthers fall off or remain hang- 

 ing like shrivelled empty bags at the end of the reflexed 

 filaments. In the course of this afternoon the filaments 

 of the five other stamens, those namely which are oppo- 

 site to the petals, lengthen in their turn ; the still-closed 

 anthers appear as before towards evening at the aperture, 

 and again by dusk they are to be seen, opened and 

 poUen-covered, projecting on their stiff straight fila- 

 ments beyond the mouth of the corolla. On the third 



