434 RESEARCHES ON FUNGI 



a needle, and then the wounds were inoculated with mycehum 

 attached to bits of agar. Infection took place ; but, in general, the 

 leaf-spots failed to develop any gemmifers. At length, on one leaf- 

 spot, two or three gemmifers made their appearance. The gemmae 

 of these gemmifers were then removed with a needle and used as 

 inoculum on a new wounded Bryophyllum leaf. The new leaf-spot 

 produced gemmifers more freely than its predecessor, whereupon 

 its gemmae were used as inoculum as before. After having been 

 passed in this way through Bryophyllum leaves several times, 

 the mycelium fruited freely, and thousands of gemmifers and some 

 scores of sporophores were obtained from it on bread and malt-agar 

 media as well as on living leaves of Bryophyllum and Oleander. 

 Nevertheless, the mycelium did not seem to be in quite so good a 

 condition as it had been three years before, because (1) it fruited 

 rather slowly, and (2) it still showed a tendency to develop a fluffy 

 mycelium at the surface of the culture medium, instead of gemmifers. 



In the spring of 1928, through the kindness of Mr. J. A. B. NoUa, 

 I obtained from Porto Rico a culture of Omjihalia flavida which had 

 recently been isolated by Professor Albert IMiiller of the Mayagiiez 

 Agricultural College. When portions of this Porto Rican culture 

 were transferred to malt-agar plates, the mycelium, unlike that from 

 Trinidad, did not develop an aerial fluffy layer of hyphae but rapidly 

 produced gemmifers. Within five days after inoculation of the 

 plates, which were exposed to light on a table, gemmifer production 

 was in full progress. A comparison showed that the newly isolated 

 Porto Rican culture fruited far more rapidly and vigorously than 

 the Trinidad culture derived from an isolation made three years 

 previously. 



From the above observations we may conclude : (1) that the 

 mycelium of Ornphalia flavida, when newly obtained from gemmae 

 developed in the open on Coffee leaves, fruits vigorously ; (2) that, 

 when the mycelium is grown for several years on artificial media, 

 it gradually loses its fruiting power ; and (3) that the fruiting power 

 in an old culture can be restored in a large measure by passing the 

 mycelium through living leaves. 



The Effect of Light on the Formation of Gemmifers.— The 

 mycelium of the Trinidad strain of Omphalia favida, after it had 



