CULTURES OF UREDINEAE IN 1911^ 



J. C. Arthur 



The present article is the twelfth of a series of reports^ by the 

 writer upon the culture of plant rusts, extending through thirteen 

 consecutive years. The preceding report for the year 1910, pub- 

 lished in Mycologia for January, 1912, contained an unfortunate 

 slip of the pen in the heading of a paragraph at the middle of 

 page 13, where " Grossulariae (Schum.) Lagerh." should read 

 albiperidia Arth. With this change, the discussion which follows 

 reads correctly. The same error occurs on page 30, twelfth line 

 from the bottom. 



The very large majority of the sowings for each year are made 

 during the months of April and May. Hot weather is inimical 

 to the work, except for a few species. Throughout the year 191 1 

 unusual high temperature prevailed ; after the first week in May 

 the thermometer ranged above 80° F. during the middle of the 

 day for the remainder of the cultural season. Owing to an un- 

 fortunate delay in securing an assistant to prosecute the work, 

 the first sowings were not made until April 19, and the work was 

 scarcely well under way before the hot days began, making it 

 nearly impossible to obtain germination of the spores, or in case 

 of germination to obtain infection of the hosts. 



The work of the season was conducted by Mr. Earl A. Trager, 

 a junior high school student of South Bend, Ind., who was recom- 

 mended by Miss Clara Cunningham, teacher of the natural sci- 

 ences in the South Bend High School. Mr. Trager conducted 

 the work admirably. He furthermore showed capacity for mas- 

 tering the technique and for handling the problems involved 

 which compared favorably with that of his more mature and 



^ Presented before the Botanical Society of America at the Washington meet- 

 ing, December 27, 191 1. 



^ See Bot. Gaz. 29: 268-276; 35: 10-23; Jour. Myc. 8: 51-56; 10: 8-21; 

 II: 50-67; 12: 11-27; 13: 189-205; 14: 7-26; Mycol. i: 225-256; 2: 213-240; 

 and 4 : 7-33- 1912. 



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