368 THALLOPHYTES 
numerous nuclei of the antheridium flow into the trichogyne and 
pass on into the odgonium where they pair and fuse with the 
numerous nuclei of the odgonium. From the fertilized oégonium, 
now known as the ascogonium, branches called ascogenous hyphae 
are developed and on the ultimate branches of these are produced 
the asci. From bencath the 
ascogonium sterile hyphae 
(hyphae producing no asci) 
grow up among the ascoge- 
noushyphae and constitute the 
paraphyses of the hymenium. 
Other sterile hyphae form the 
wall of ‘the cup-shaped plant 
body or ascocarp. Usually 
several oégonia are involved 
in the formation of a single 
ascocarp. , 
Brown Rot of Stone Fruits 
(Sclerotinia fructigena). — 
This Fungus, shown in Figure 
319, is one of the parasitic 
8 forms of the Pezizales. In 
ag Ey some years this Fungus is an 
Z extremely destructive para- 
site. It attacks nearly all 
stone fruits and in some years 
Fic. 319. — Sclerotinia fructigena. nearly half of the Plum and 
Above, the apothecia developed on a Peach crop may be destroyed 
decayed Plum; at the right, below, by this disease. In Georgia 
section through an apothecium, show- hie estimdted less du Peaches 
ing asci and paraphyses; at the left, 
below, an ascus and paraphysis more and Plums caused by this 
highly magnified. After Duggar. disease in 1900 was between 
$500,000 and $700,000. Toa 
limited extent it attacks the twigs and flowers and does some 
damage in this way. 
Fruits half size or larger seem to be most susceptible to the 
attack of the Fungus. The disease first shows as small decayed 
spots, dark brown in color. The fruit decays rapidly and soon 
hyphae break through from beneath, forming moldy patches on 
the surface. The moldy patches contain conidiophores which 
Hae 
