442 RESEARCHES ON FUNGI 



The fungus, on being examined by Hennings, proved to be an 

 Omphalia, and it was named in honour of Professor Martens, its 

 discoverer. The fruit-body has a stipe 2-2-5 cm. high and 

 0-5-1 mm. thick, while the pileus is 5-9 mm. in diameter. 

 Evidently, the fruit-bodies of 0. Martensii are more than double 

 as large as those of 0. flavida. The two fungi also differ in 

 their luminescence, for the light is emitted by 0. Martensii 

 from the sporophore and by 0. flavida from the mycelium and 

 gemmifers. 



The full description given by Hennings for Omphalia Martensii, 

 translated from the Latin, is as follows : " Pileus membranaceous, 

 campanulate, umbilicate in the centre, radiately striate, dirty yellow- 

 ish, 5-9 mm. in diameter ; stipe thin, hollow, smooth and glabrous, 

 yellowish, subfuscous at the base, 2-2-5 cm. long, 0-5-1 mm. 

 thick ; gills subtriangular, broad, subdistant, pallid, decurrent ; 

 spores not seen. Habitat : west Borneo, near Bengkajang, on 

 roots." 



In view of the fact that the mycelium of Omphalia flavida makes 

 Coffee and other kinds of leaves luminous, one may well ask whether 

 or not the mycelium of similar fungi is the cause of the luminosit}' 

 which may be observed in dead leaves of Beech, Oak, Hornbeam, 

 etc., forming part of the leaf-mould of the broad-leaved forests ^ 

 very generally throughout the world.^ This question has recently 

 been answered in the affirmative by Bothe. 



Bothe 3 has discovered that the mycelium of the following species 

 of Mycena emits light : M. jjolygramma Bull, and M. tinUnnabulum 



1 Most observers have sought for kiniinous leaves only in broad-leaved forests, 

 but Bothe (1931, in Planta, p. 753, vide infra) has discovered that they also occur in 

 coniferous forests. In various places in the neighbourhood of Braunschweig and 

 in the Harz under Pines, etc., he found needles of conifers, little twigs, and isolated 

 " Tannen " cones, which gave out light just as strongly as decaying Beech and Oak 

 leaves. 



2 In 1924, in Volume III of these Researches (pp. 421-427), to France, Germany, 

 and Sumatra I added England, Canada, and the United States as countries in which 

 luminous leaves occur. In 1926, S. R. Bose {Nature, 1926, p. 156) added India 

 (Bengal). Here also it may be recorded that in 1929 I observed luminous Beech 

 and Oak leaves in Scotland (Loch Awe) and in 1931 in Ireland (near Belfast). 



3 F. Bothe, " Ein neuer einheimischer Leuchtpilz," Bcr. d. D. lot. Gesell, Bd. 

 XLVIII, 1930, pp. 394-399 ; also " Uber das Leuchten verwesender Blatter und 

 seine Erreger," Planta, Bd. XIV, 1931, pp. 752-765. 



