NINETEEN YEARS OF CULTURE WORK 1 



J. C. Arthur 



A series of culture experiments with the Uredinales was begun 

 by the writer in 1899, and continued under the auspices of the 

 Indiana Agricultural Experiment Station without interruption 

 until 1917, making nineteen consecutive years in which this 

 method of research was consistently pursued. The results of the 

 work were embodied in fifteen reports, printed in the Botanical 

 Gazette, Journal of Mycology, and Mycologia. It is now pro- 

 posed very briefly to review the work, in order to set forth some 

 of the objects accomplished, and especially to point out the more 

 important of the changing conceptions of the problems forming 

 the ground plan on which the work was projected. 



The cultures were not undertaken as part of a distinct thesis 

 or circumscribed problem. They were rather the aids in a gen- 

 eral taxonomic study of American rusts, which was directed 

 toward supplying a technical description as complete as possible 

 for every species of Uredinales in North America recorded in 

 literature or known to the writer. This ambitious undertaking 

 was definitely begun sometime in the nineties at the invitation of 

 the editors of the North American Flora. 



Beginning with my first taxonomic work on the rusts in 1882 it 

 had seemed to me highly desirable for the purposes of a full tech- 

 nical description of species, that every part of these microscopic 

 plants, capable of supplying diagnostic characters, should be uni- 

 formly considered, quite as much as are the stems, leaves, in- 

 florescence, flowers, and fruit of higher plants, and that every 

 means should be taken to arrive at a clear understanding of the 

 identity and relationship of the various forms and species. No 

 effort should be spared, it was believed, to make the name ap- 

 plied to any form embrace also the transformations and variations 



1 Contribution from the Botanical Department of Purdue University Agri- 

 cultural Experiment Station. 



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