GRAPE DISEASES 251 
In the event that half-grown berries are attacked they become 
irregular in shape. 
The leaves and other parts of the vine when affected by 
anthracnose show lesions similar to those already de- 
scribed on the shoots. Spots on the foliage are pale-gray 
with dark-red borders. Cankers are produced on the petioles 
and veins. 
Cause of anthracnose. 
The lesions described above are due to the fungus Gleo- 
sportum ampelophagum (=Sphaceloma ampelinum). In America 
only one spore-stage is known; in France, plant pathologists 
claim to have discovered a winter’ sexual spore-stage. Ac- 
cordingly, the name Manginia ampelinum has been substituted. 
The similarity of the grape-anthracnose fungus to the black- 
berry and raspberry-anthracnose fungus has resulted in one 
case, at least, in the suggestion of the possible identity of the 
two organisms. 
The mycelium of the fungus grows within the affected tissue. 
Certain threads come to the surface and form fruiting bodies 
called acervuli. These structures burst through the skin of 
berries and canes, sending out many erect conidiophores on which 
conidia are produced. These spores ooze out in a gelatinous 
mass held together by their sticky coatings. The sticky sub- 
stance dissolves in water and the spores are thus liberated. 
They are disseminated by rain and dew, the process occur- 
ring from the time the berry clusters are yet in the bud 
until the close of the season. Spores falling on green 
parts of the vine germinate, and after about a week signs 
of the anthracnose disease begin to appear. The germ- 
tubes penetrate the healthy, unbroken epidermis. With 
the advent of the dormant season the fungus apparently 
ceases activities. It is not definitely known how the fun- 
gus passes. the winter, but the supposition is that it hi- 
bernates as mycelium in lesions on the canes and mummied 
