FREAKS OF PLANT LIFE 383 



CHAPTER XVIII. 



LUMINOSITY. 



THE phenomena of " luminosity '' in plants are 

 evidently variable in their causes, as predicated by 

 the variability of the results. We have brought 

 together examples of these manifestations from 

 flowering and cryptogamic plants, associated some- 

 what in accordance with their apparent relationship, 

 but without any effort at explanation. There is 

 strong presumption that some of the supposed cases, 

 of flashes of light from bright coloured flowers, may 

 be explained optically. Others can be accounted 

 for by no such hypothesis. The different facts seem 

 to group themselves thus : — Flowers exhibiting 

 electrical flashes of light on sultry evenings ; plants 

 becoming surrounded by the vapour of essential 

 oil, which readily takes fire ; roots, or rhizomes, 

 which, under certain conditions are luminous ; 

 and fungi which are either luminous in their 

 imperfect, or " mycelium " condition, or when fully 

 matured. 



The luminosity of flowers, under certain conditions, 



