352 LUMINOSITY IN PLANTS. 



portant part in the striking- spectacle of marine phospliorescence ; and 

 if we ignore the so-called glimmer of flowers, first observed by the 

 daughter of Linnaeus, which is attributable to an entirely different 

 cause, j^robably a purely physical one, and most likely to the appear- 

 ance of St. P]lmo's fire, all light-producing plants may be said to 

 belong to the Fungi ; that is, to the Bacteria and the mycelial Fungi. 



In order to avoid misunderstanding it may be said that in speak- 

 ing of light-producing 2:)lants I refer invariably to those plants which 

 of themselves produce the light, their own and not reflected light, to 

 which latter phenomenon are to be referred the wonderful iridescence 

 of many sea alga^, the remarkable emerald green gleam of the lumi- 

 nous moss Schistostega Of<mi/ndacea, and the reflection, like liquid 

 gold, of the Flagellate, Chromophyton roscuiofii There are in 

 round numbers thirty different kinds of bacteria and about half as 

 many other fungi which have the power of luminosity. If we com- 

 pare this to the combined number of existing plant species they 

 doubtless aj^pear as a very small proportion. Nevertheless we are 

 frequently surrounded with luminous objects in nature and even in 

 the household, because certain ones of these light-producing fungi are 

 among the most common of all plants. Of these I will give a couple 

 of examples. 



Until recently luminosity in butchers' meat was considered to be 

 a spectacle of rare occurrence, a curiosity the cause of which was un- 

 known and the conditions jH'oducing it infrequent. When I under- 

 took an investigation of the matter I lacked proper material ; and 

 although I conununicated with various people and institutions where 

 luminous meat would be most likely to be found, not a single specimen 

 was supplied to me for fully two years. I was about ready to aban- 

 don the undertaking when the idea came to me to examine meat 

 supplied to me for household use, and to my astonishment it appeared 

 that such meat, kept for from one to three days in a cool place, began in 

 many instances to spontaneously produce light. In following up the 

 matter I found that the luminosity nuich more frequently occurred 

 if ordinary butchers' meat was so immersed in a ?> per cent solution of 

 salt that about one-half of it remained out of the liquid. Experi- 

 ments with meat carried on for three months afforded not less than 

 87 per ceut of cases of luminosity ; thus, experiments with beef afforded 

 89 per cent, experiments with horseflesh ()5 per cent. By means of pure 

 cultures it was demonstrated that the cause of the luminosity was 

 invariably the same intensely luminous bacterium, namely, Bacterhim 

 'pliosfhoreunh (Cohn) Molisch. As I'have carried on similar researches 

 for a number of years, not only in the city of Prague but in other 

 cities as well and with essentially the same results, it can be stated 

 that the spontaneous luminosity of meat is in fact a quite common 

 occurrence. 



