FRUCTIFICATION IN MOLDS 203 
vegetative. Fertile hyphe are those which bear the fruiting body and 
produce the spores. The vegetative hyphez secure the nutriment and 
get rid of the excess moisture. 
The structure of the hyphe differs among the molds. Some have 
cross walls or septa. In other molds these have not been observed. 
The presence or absence of these septa is an important factor in the 
Fia. 47 —Rhizopus nigricans Ehrenberg (After Brefeld ) 
(a) is the extremity of a stolon, which has developed into the appressorium (h) This latter 
is the starting point of the sporangiophores (t) four of which are shown with the sporangia (s) 
unbroken, whilst the columella (¢) 1s all that remains of the fifth Magn 30 
identification of molds. The mucoraceez do not possess these cross 
walls ordinarily. 
Fructification. This takes place on the fertile hyphe which bear 
the fruiting bodies. Enormous numbers of spores are formed each of 
which may develop into a typical mold plant. The spores are of two 
kinds, sexual and asexual. 
The sexual spores are formed by the union of two cells. The result- 
ing cell then possesses the characteristics which are algebraic sums of 
