4i8 



RESEARCHES ON FUNGI 



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Molisch came to the conclusion that Xylaria Hyimxylou is non- 

 luminous and Gueguen that the fungus distinctly gives out light. 



How shall we harmonise 

 these diametrically opposite 

 results ? It is possible that 

 Molisch and Gueguen were 

 both working with essentially 

 the same form of the fungus 

 and that the difference in 

 their results was due to a 

 difference in the composition 

 of their culture medial How- 

 ever, it may be that the two 

 workers employed two differ- 

 ent physiological forms, that 

 of Gueguen being a luminous 

 one and that of Molisch non- 

 luminous. According to this 

 explanation, the French and 

 German forms of Xylaria 

 HypoxyJon correspond respec- 

 tively to the North American 

 and English forms of Panus 

 stypticus, in that the former 

 has an internal metabolism 

 which results in biolumines- 

 cence, whereas the latter has 

 not. To determine with 

 absolute certainty whether 

 some forms of X. Hypoxylon 

 are luminous while others are not, it will only be necessary to 



1 That the medium upon which the mycelium grows may affect the intensity 

 of the light given out by a luminous fungus is sho\vn by some facts recently commu- 

 nicated to me by Dr. A. W. McCallum of Ottawa. Dr. McCallum found that the 

 mycelium of Armillaria mellea was " strongly phosphorescent when growing on spruce 

 wood and bread soaked in prune juice, and apparently not so when grown on such 

 media as potato and corn-meal agars." But he adds: "Recently, however, I 

 have observed that this fungus is faintly luminous on potato -dextrose agar." It 



Fig. 178. — A fruit-body of Xylaria poly- 

 morjiha. The swollen portions, just 

 beneath the surface, contain numer- 

 ous peritliecia whicli emit ascospores 

 througli fine ostioles opening on the 

 exterior. In 1882 Crie asserted that 

 the mycelium of this fungus is lumi- 

 nescent. Photograplied by A. E. Peck 

 at Scarborough,England. Natural size. 



