452 REroRT of the Mycologist of the 



Some species of Macrosporimn are known to have a second 

 kind of spores which are borne within sacs (asci) enclosed in 

 an envelope called a perithecium. In other species this asciger- 

 ous form is unknown. It has never been observed in M. hercu- 

 leum. Some of the turnip leaves affected with M. Iierculeum were 

 put in cheese-cloth bags, which were then placed on the ground 

 out of doors and left there during the winter. The following 

 spring the leaves were carefully examined for perithecia, but 

 none could be found. 



During late summer of the past season the foliage of horse- 

 radish on Long Island was quite generally affected with Mac- 

 rosporium disease and was probably somewhat injured by it. 

 However, it is not likely that either the flat turnip or the horse- 

 radish is injured suflSciently to warrant the expense of spraying. 

 Should treatment seem advisable, nothing is more likely to prove 

 successful than Bordeaux mixture, applied before the disease 

 makes its appearance. 



Blight of Corn Leaves. 



The white blast or leaf-blight of corn has been so common this 

 season as to attract the attention of farmers, who attributed 

 the cause to a period of unusually hot weather which occurred 

 in August. Both sweet corn and field corn suffered; in some 

 cases so severely as to materially lessen their value for fodder 

 and to prevent the ears from maturing properly. Diseased leaves 

 have somewhat the appearance of having been frost bitten. 



The primary cause of the disease is a parasitic fungus, Eel- 

 minthosporlum inconspicuum C. & Ell., which may be seen grow- 

 ing on the under surfaces of the diseased spots in the form of a 

 delicate olive-green mould. The appearance of the fungus, when 

 magnified, is shown at Fig. 2, plate XXXIL '' Weather " can not 

 be held responsible for the disease except that certain weather 

 conditions (usually warm, wet weather) are more favorable than 

 others for the development of the Helminthosporiuni. 



There is another disease of sweet corn which may be mistaken 

 for the Helminthosporium disease. This other disease is an un- 



