446 RESEARCHES ON FUNGI 



Coremium disease is a misnomer. Since the fungus produces 

 characteristic sclerotia, it is better to follow Stahel and call the 

 disease the Sclerotiuni disease. 



Sderotium coffeicola attacks both the leaves and the berries of 

 the Coffee plant, and its ravages, in very moist weather, may even 

 extend to the inflorescences and flower-buds. The berries are affected 

 only when they are about three-quarters grown and are beginning 

 to ripen. On the leaves, like Omjjhalia flavida, Sderotium, coffeicola 

 causes the formation of brown leaf-spots (Figs. 224 and 225). These 

 spots are characterised by the presence of concentric rings and by 

 the production of gemmifers. The rings are due to the alternation 

 of narrower lighter brown zones of dead tissue with broader darker 

 brown zones. So long as the diseased leaves are hanging on the tree, 

 the gemmifers are produced only on the under side of the leaf -spots. 

 In the morning, after a dewy night, they can be seen on the lower 

 surface of each spot standing uJD in large numbers and more or less 

 in concentric circles (Fig. 225). The gemmifers are also produced 

 in dense crowds on diseased berries and sometimes on the peduncles 

 (Fig. 226). 



On fallen leaves, in moist weather, the mycelium often grows 

 out centrifugally from the leaf-spots over the surface of the 

 leaves in the form of feathery branching strands which pro- 

 duce numerous gemmae (Fig. 227) ; and, in continuously moist 

 weather, this may happen even on leaves still hanging on the 

 trees. 



Each gemmifer consists of a little white knob-like pedicel, 

 attached to the substratum, and of an apical gemma. The gemma 

 takes the form of a slender white cylindrical needle which ends in 

 a blunt point. The gemmae on the leaf-spots are 1 • 5-4 • mm. long 

 and 0- 05-0-1 mm. thick, i.e. about forty times as long as broad, 

 while those on the fruits are shorter and thicker — about 1-2 mm. 

 long and 0-08-0 -2 mm. thick. 



There can be no doubt that the gemmifer of Sderotium coffeicola, 

 like that of Om2)halia flavida, is entirely sporeless, so that, whatever 

 its evolutionary origin, at the present day it does not serve as a 

 sporophore. Since it is an active organ, obviously functioning by 

 producing a multicellular body which is able to propagate the 



