PHANEROGAMIC PLANTS. 83 



quently seen on the same flower two or three 

 times in quick succession, but more commonly at 

 intervals of several minutes; and when several 

 flowers in the same place emitted their light to- 

 gether, it could be seen at a considerable dis- 

 tance. This phenomenon was remarked in July 

 and August at sunset, and for half an hour, when 

 the atmosphere was clear ; but after a rainy day, 

 or when the air was loaded with vapours, nothing 

 of it was seen. The fact of this phenomenon only 

 occurring when the air is dry, leads us naturally 

 to presume that it is connected with electricity. 

 The following flowers were observed by M. Hag- 

 gern, to emit flashes more or less vivid, in this 

 order : 1. The marigold (Calendula officinalis, 

 fig. 7). 2. Monkshood, or garden nasturtium (Tro- 

 pceolum majus). 3. The orange lily (Lilium bulbi- 

 ferum, fig. 8) . 4. The French and African mari- 

 golds (Tagetes patula and T. erecta). 



To discover whether some little insects or 

 phosphoric worms might not be the cause of this 

 emission of light, M. Haggern carefully examined 

 the flowers with the microscope, but no animal 

 organisms were found. The rapidity of the flash 

 seems to indicate that electricity has something to 

 do -with the phenomenon. The same philosopher, 

 after having observed the flash from the orange 

 lily, the anthers of which are a considerable dis- 

 tance from the petals, assured himself that the 



