30 Thirty-fourth Annual Report of the 



to indicate the best methods of preventing the attack of these fungi 

 on cultivated plants. 



Another name, Puccinia Sorghi, Schw., is sometimes applied to the 

 fungus under consideration, but as Schweinitz employed it to desig- 

 nate also a fungus found on the leaves of Sorghum, and as I have not 

 been able to ascertain positively whether the Sorghum fungus is 

 really identical with the Indian corn Brand, I have thought it best to 

 employ for this the name Puccinia Mayclis. 



The three fungi already noticed as inhabitants of Indian corn are 

 by no means all the species that attack it in the living state, but they 

 are the most common ones that infest it in this vicinity. One or all 

 of them can be found in almost every corn field in the latter part of the 

 season. Many other species occur on the dead stalks and leaves, es- 

 pecially when left lying in damp places. 



Kamularia Fragariae, Ph. Strawberry Ramularia. (Plate 3, figs. 

 12-15.) It is by no means an unusual thing to find the leaves of straw- 

 berry vines, both cultivated and wild, marked with nearly circular spots. 

 These spots have a pale or whitish center in which the leaf tissues ap- 

 pear to be dry and dead. They are not ordinarily much more than an 

 eighth of an inch in diameter, but they are surrounded by a broad 

 border which is dark-red or brownish -red. When the spots are nu- 

 merous these colored borders run into each other and form discolored 

 patches on the leaf. Sometimes the discoloration runs out to the mar- 

 gin of the leaf in a broad stripe. On the lower surface of the leaf the 

 central part of the spot is not usually as pale as on the upper surface. 

 To an ordinary observer the spots alone are seen. The cause of them 

 remains a mystery. Some have supposed them to be produced by the 

 scalding heat of the' sun, others by the stings of insects, and others 

 have intuitively imagined that possibly they might be caused by a 

 fungus, and have alluded to them as the "strawberry rust." A fungus 

 indeed does produce them but it is not a true " rust-fungus." It is one 

 so small and so well protected from observation by the similarity be- 

 tween its own color and the color of the spot that untrained eyes will 

 scarcely detect it. If, however, the white or central part of the spot 

 be examined with a magnifying glass it will generally be found to be 

 frosted over with minute white flocculent tufts or mealy-looking par- 

 ticles. This is the fertile condition of the fungus. It may not always 

 be found in fertile condition. If sterile, nothing but the spot will be 

 seen. The fungus consists of three parts : first, the creeping filaments 

 which permeate the cells of the leaf, destroying their vitality and natu- 

 ral color; second, the minute tufts of short, upright stems, usually 

 simple, but sometimes branched ; ,and third, the long, narrow spores 

 which are borne at the top of the stems. The spores are cylindrical, 

 and about eight or ten times as long as broad. They are generally 

 straight and simple, but occasionally one occurs which is slightly 

 curved or which maybe divided near the middle by one or two obscure 

 transverse partitions. The spores and stems make up the minute white 

 flocculent masses seen upon the surface of the spot. The latter are 

 usually, a little thicker than the former, but there is not much differ- 

 ence in the length of the two. They are found on both surfaces of the 

 leaf, but are more abundant on the upper surface. The fungus occurs 



