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the mycelium remains in a more or less dormant state until conditions are 
favorable for the germination of the bean seed, when it renews its activity. 
An examination of a diseased seed will reveal an abundance of my- 
celium in the infected portions. By carefully treating the seed with hot 
water or formalin to rid them of surface fungi and placing them in a 
sterile moist chamber, one is able to obtain spores in great profusion on 
the seed before it has germinated and later on the cotyledons, stems and 
leaves of the seedling in the sunken and discolored cankers caused by the 
fungus. Dr. Halstead reports that he has found spores of the Anthracnose 
on the dry beans, especially in the cavity between the cotyledons. 
In the germinating plant, no doubt the plumule is often infected by 
contact with the diseased portions of the cotyledons. (Fig. 3.) Spores, 
however, are produced upon the cotyledons after the bean has expanded 
its true leaves and when released by the dissolution of the mucilaginous 
matrix they are washed to the ground or on the stems below. The stems 
become infected from these spores and cankers are formed at the infected 
places. Often these cankers encircle the stem and thus cut off the supply 
for the leaves above. Sixty-one German Wax Beans apparently healthy 
were planted in the greenhouse. When well up five were observed which 
had infected cotyledons, the others appearing healthy. Seventeen days 
after planting thirty-one of the plants were affected by the disease at the 
base of their stems, showing, doubtless, that spores from the cotyledons 
of the five plants had infected the stems of the others. (Fig. 4.) 
When the plants are moist the spores of the fungus are in a condition 
to be easily disseminated, so that working among the plants at this time or 
otherwise disturbing them aids in the dissemination of the fungus if any 
diseased plants are present. Even the wind aids dissemination by scatter- 
ing contaminated drops of water to healthy plants, or by blowing the plants 
against each other. In this way the disease spreads to the leaves, stems 
and pods of the plant during the growing season. 
The selection of seed from unaffected pods seems at present to be the 
most satisfactory method to pursue in controlling the disease. The pods 
should be selected in the field and only such as are perfectly free from all 
evidence of disease should be selected. Apparently healthy beans within an 
infected pod may harbor the mycelium of the fungus without showing any 
evidence of it. Enough seed can be selected in this way to plant small 
patches. Those who grow large areas should select enough beans to plant 
1. Halstead, B. D., The Anthracnose of the Bean. A Remedy Suggested. Ann. 
Rept. N.J. Agr. Exp. Sta. 1891, p. 284. 
