^36 STUDIES OF AMERICAN FUNGI. 



Clitocybe illudens (see Fig. 92) has long been known to emit a strong 

 phosphorescent light, and has been called " Jack-my-lantern." 

 This plant often occurs in great abundance. At mountain hotels it 

 is often brought in by day, and the guests at night, discovering its 

 luminosity, trace grotesque figures, or monograms, on the ground 

 by broken portions, which can be seen at a considerable distance. 

 Lentinus stipticus in this country is also phosphorescent. In Europe, 

 the Pleurotus olearius (very closely related to our Clitocybe illudens) 

 on dead olive trunks is one of the best known of the phosphorescent 

 species. Other phosphorescent species are, according to Tulasne, 

 A. igneus from Amboyna, A. noctileucus in Manila, and A. gardneri 

 in Brazil. 



The use of certain mushrooms in making intoxicant beverages is 

 referred to in Chapter XXII. 



Since the artificial cultivation of mushrooms for food is becoming 

 quite an industry in this country with some, the following chapter 

 is devoted to a treatment of the subject. Mention may be made 

 here, however, of the attempts in parts of France to cultivate 

 truffles, species of subterranean fungi belonging to the ascomycetes 

 (various species of the genus Tuber). It had long been observed 

 that truffles grow in regions forested by certain trees, as the oak, 

 beech, hornbeam, etc. Efforts were made to increase the production 

 of truffles by planting certain regions to these trees. Especially in 

 certain calcareous districts of France (see Cooke, Fungi, etc., p. 

 260) young plantations of oak, beech, or beech and fir, after the 

 lapse of a few years, produced truffles. The spores of the truffles 

 are in the soil, and the mycelium seems to maintain some symbiotic 

 relation with the roots of the young trees, which results in the 

 increase in the production of the fruit bodies. Dogs and pigs are 

 employed in the collection of truffles from the ground. 



Comparatively few of the truffles, or other subterranean fungi, 

 have been found in America, owing probably to their subterranean 

 habit, where they are not readily observed, and to the necessity of 

 special search to find them. In California, however, Dr. Harkness 

 (Proc. Calif. Acad. Sci.) has collected a large number of species and 

 genera. Recently (Shear. Asa Gray Bull. 7: 118, 1899) reports 

 finding a ''truffle' 1 (Terfc^ia oligospemu Tul.) in Maryland, and 

 T. leonis occurs in Louisiana. 



