62 MYCOLOGY 



fructification does not seem to be affected by the light conditions, 

 but here the evidence is contradictory, some fructifications being 

 formed better in light than in the dark and vice versa. Kolkwitz after 

 eliminating various sources of error of earlier experimenters found 

 that in his cultures of Aspergillus niger and Oidium ladis that con- 

 siderable acceleration of respiration is experienced with a brief illumina- 

 tion by a powerful electric arc. Koernicke^ finds that Roentgen rays 

 inhibit the growth of fungi with prolonged action. 



Luminosity of Fungi. — The luminosity of wood and decaying logs 

 in the forest is associated with the mycelia of certain fungi. The 

 phenomenon is connected frequently with gill-bearing fungi, such 

 as Agaricus, Armillaria mellea, Pleurotus olearius, and as determined by 

 Molisch with the two ascomycetous fungi. Xylaria hypoxylon and A^. 

 Cookei. In order to prevent any error arising in the experiments 

 through the presence of luminous bacteria, Molisch^ grew Armillaria 

 mellea, Xylaria hypoxylon, X. Cookei, Mycelium X. in pure cultures, 

 the latter succeeding well on bread. He found that under such con- 

 ditions the plants became phosphorescent. Such phosphorescence 

 is connected with a supply of oxygen and is not due to the separation 

 of some luminous substances, but is intracellular in its origin. 



Liberation of Spores.— The spores of the gill fungi (HYMENOMY- 

 CETES) are very adhesive, when freshly set free. As a result of 

 this, special arrangements are found for the liberation of the spores 

 from the surfaces of the gills and the hymenial tubes. Paraphyses 

 between the special conidiophores known as basidia serve to increase 

 the spaces between the spores, preventing contact and allowing a 

 freer fall of the spores. The arrangement of the gills is such as to 

 economically increase the spore-bearing surface, and, therefore, the 

 total number of spores that a fruit body can produce. By various 

 growth movements of the cap and fruit stalk, the spore-bearing sur- 

 face is placed in the best possible position for the liberation of spores. 

 The spores liberated from the gills on the under surface of a pileus 

 placed over a horizontal sheet of paper fall vertically downward and 

 form a spore print, which consists of radiating lines corresponding to 

 the inter-lamellar spaces. The number of spores set free by large 

 fruit bodies is prodigious. A specimen of the mushroom Agaricus 



1 KoERNiCKE, Max: Ber. d. deutsch. Bot. Ges., 1904: 22, 14H. 



2 Molisch, Hans: Leuchtende Pflanze, 1904: 25-46. 



