USTILAGO MAIDIS. 



Ill 



quite recent, and so has very little history. It is not recognized by 

 the U. S. Pharmacopoeia. 



It is found as a smut growing on almost all parts of corn. The 

 stem, the leaf, the flower, the fruit alike are troubled with this 

 plague. It seems to prefer for its host only tall, healthy plants, and 

 everywhere it takes the most spacious room for its accommodation. 

 It first attacks the summit of the plant or the anthers, and then grad- 

 ually spreads until the whole plant above the ground is affected. 

 It has never been found in the ovary or the walls of the ovary of the 

 pistillate flower, or in the staminate flower of the Zea Mays ; but it 

 is found in every other part of the plant. (See Ann. des Sci. Nat. 

 Vol. VII, Ser. Ill, page 85.) As soon as the fruit is attacked the 



Fig. 2. 



outer wall begins to swell out in a most wonderful and grotesque 

 manner, sometimes the affected kernel will change from its natural 

 size to that of the fist. It occasionally turns to a deep red, and if 

 broken gives out a sooty fluid having a somewhat bloody appear- 

 ance. As it grows older this mass looks like a finely pulverized 

 black soot, with the parenchyma and the vascular woody fibres yet 

 present in the powder. 



Fig. i represents an ear of Indian corn affected with Ustilago 

 Maidis. The disease has affected the whole ear in such a way that 

 it can never develope into healthy fruit. The little bracts on the 

 affected part are tumified by the presence of the smut, and are 

 developed in the most abnormal shapes. The whole outer surface is 



