48 



FUNGI. 



the sclerotia is late in the autumn, after the fall of the vine 

 leaves. As long as the frost does not set in, new ones continu- 

 ally spring up, and each one attains to ripeness in a few days. 

 If frost appears, it can lie dry a whole year, without losing 

 its power of development. This latter commences when the 

 sclerotium is brought into contact with damp ground during 

 the usual temperature of our warmer seasons. If this occur 

 soon, at the latest some weeks after it is ripe, new vegetation 

 grows very quickly, generally after a few days ; in several parts 

 the colourless filaments of the inner tissue begin to send out 

 clusters of strong branches, which, breaking through the black 

 rind, stretch themselves up perpendicularly towards the surface, 

 separate from one another, and then take 

 all the characteristics of the conidia-bearers. 

 Many such clusters can be produced on one 

 sclerotium, so that soon the greater part of 

 the surface is covered by filamentous conidia- 

 bearers with their panicles. The colourless 

 tissue of the sclerotium disappears in the 

 same degree as the conidia-bearers grow, 

 and at last the black rind remains behind 

 empty and shrivelled. If we bring, after 

 many months, for the first time, the ripe 

 sclerotium, in damp ground, in summer or 

 autumn, after it has ripened, the further 

 development takes place more slowly, and 

 in an essentiall 7 different form. It is true 

 that from the inner tissue numerous fila- 

 mentous branches shoot forth at the cost of this growing 

 fascicle, and break through the black rind, but its filaments 

 remain strongly bound, in an almost parallel situation, to a 

 cylindrical cord, which for a time lengthens itself and spreads 

 out its free end to a flat plate-like disc. This is always formed 

 of strongly united threads, ramifications of the cylindrical cord. 

 On the free upper surface of the disc, the filaments shoot forth 

 innumerable branches, which, growing to the same height, thick 

 and parallel with one another, cover the before-named disc. 



FIO. .-* 



ridia. 



