LUMINOSITY IN PLANTS.'' 



By Prof. Dr. Hans Molisch. 



Sixty-two years ago, at the twenty-first meeting of German 

 scientists and jDhysicians at Gratz, over Avhich no less a personage 

 than the famous chemist, J. von Liebig, presided, an Austrian investi- 

 gator, J. T. Heller, gave an address upon the luminosity of decaying 

 wood, and advanced the idea that the production of light did not 

 come from the decaying wood itself, but from a fungus wdiich pene- 

 trated the wood. Not long after this the same investigator carried 

 out a thorough examination of liglit coming from decaying animals 

 and plants, and discovered that the luminosity in the flesh of dead 

 marine animals and various decaying jjlant substances was not a 

 purely chemical but a biological process, uniformly produced by a 

 certain plant, a fungus. That is to say, it is not the flesh of a fish 

 or the wood that is luminous, but a fungus living upon these and 

 penetrating them in proportion to their decay. It may be noted 

 that priority for this discovery has been accorded, though unjustly, 

 to the gifted physiologist, E. Pfliiger, because Heller's investiga- 

 tions dropped entirely out of sight, and were only recently discovered 

 by me. The priority unquestionably l)elongs to Heller. 



By understanding that the problem is a biological one, an im- 

 portant basis has been gained for further investigations. As, fur- 

 thermore, R. Koch has enriched scientific knowledge by his bacterio- 

 logical technique and the method of pure cultures of bacteria, the cul- 

 tivation of various light-producing bacteria and recently also of lumi- 

 nous fungi has been successfully undertaken. We are now in condition 

 to approach the subject of distinguishing between various species, of 

 investigating the conditions for luminosity, the nature of the light, 

 and the problem of light development. If we exclude light develop- 

 ment in the Peridinece, which are sometimes referred to the animal 

 and sometimes to the vegetable kingdom and which play an im- 



a Translation of Die Lichtenwicljolunjj: in den Pflanzen, von Prof. Dr. ITans 

 Molisch, Leipzig, 1905. 



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