RASPBERRY DISEASES 409 
speck develops on the end, but soon the entire surface is 
involved. As the fruit matures the surface of the lesion 
becomes depressed. If affected while small, the drupels 
remain firm and finally become dry. Fruit-pedicels may be 
attacked, in which case the fruit dries up and dies. 
Cause. 
The anthracnose lesions just described are caused by the 
fungus Gleosporium venetum. Details of its full life-history are 
as yet unpublished, but the facts as generally known will be 
discussed. The winter is spent in the canes. It is very 
likely that in addition to mycelium, immature fruiting structures 
are concerned in this connection. In the spring conidia are 
formed on the old diseased areas by the fungus. These spores 
are disseminated about the time the plants are from six to ten 
inches high. Apparently the exact origin of the conidia is not 
generally known. The perithecial stage has recently been 
described, but as yet is not named. The ascospores developed 
within the perithecia are shot forcibly into the air and later 
germinate by budding. These buds are identical with the 
conidia; they may be referred to as such. Conidia probably 
also are developed in acervuli. These spores’ attack and 
their germtubes penetrate only the tender growing parts of the 
cane, as evidenced by the smaller and younger spots at the tip 
and the older ones at the base (see Symptoms). Following the 
germination and penetration processes mycelium ramifies in 
the cortex of the cane where the cells are killed. Subsequently 
conidial fruit-bodies are developed from which conidia are 
liberated. These initiate secondary infections on the canes, 
leaves and fruits. ‘These secondary infections continue 
throughout the summer. In the winter the fungus again 
remains dormant in the canes. 
Control. 
Diseased canes should be eradicated before the spring season. 
It is preferable that this be done at the end of the fruiting-sea- 
