108 Mortier F. Barrus 



often raised, center, which sometimes splits open disclosing the affected 

 cotyledon. The spots may occur on any part of the seed coat, and may 

 appear as' a small black or brown speck or involve more than half the 

 surface. In badly diseased seeds the lesion extends through the cotyledon 

 and may even affect the embryo, but in many cases the cotyledon is 

 but slightly or not at all discolored. 



On the seedlings 

 Seedlings from badly diseased seed show blackened cankers on the 

 cotyledons (fig. 10), in which, under moist conditions, small flesh-colored 

 masses appear scattered over the surface of the lesions. The stem may 

 become affected along its entire length, but usually it is affected only 

 below the point of the attachment of the cotyledons. The first indication 

 of a lesion is the appearance of brown specks in the epidermis. Later 

 there appears a browning of the tissues lengthwise of the stem and below 

 the epidermis. Still later, small pits appear along the affected area. 

 Occasionally these cankers become so deep or so numerous that the stem 

 is unable to support the parts above. 



On the leaves 

 The leaves (figs. 10 and 11) not infrequently become badly affected. 

 The lesions appear on the veins, usually on the underside of the leaf. 

 These lesions have practically the same appearance as those on the stem. 

 The tissues on each side of an infected vein and beyond it may wither 

 and die. A considerable area of a leaf may become affected in this manner, 

 giving it somewhat the appearance of blight. Usually only a small part 

 of the leaf tissue is killed, and such places appear on the upper side as 

 angular, elongated, dead areas, which sometimes become torn, giving 

 the leaf a ragged appearance. The petiole may become so badly affected 

 that it cannot support the leaf blade. 



On the roots and other parts 

 The roots of plants growing in the soil are rarely if ever affected; but 

 on seeds sprouted in a moist chamber, where the young roots are exposed, 

 lesions similar to those on the stem may be produced by artificial inocula- 

 tion. Muncie (1914: 4) mentions a rotting of the root due primarily to 

 the anthracnose and blight organisms followed by secondary rot-producers 



