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Dr. F. D. Fromme presented the first paper on the announced 

 scientific program on "Methods of Predicting Probable Life 

 Histories of Rust Species." 



The following abstract was prepared by the speaker: 



"The possession of more than one spore form in the life-cycles 

 of most rust species together with the heteroecious habit of a 

 large number of them makes the working out of their life his- 

 tories a difficult problem. This is especially true of the heteroe- 

 cious rusts, as cultures are in all cases necessary to the establish- 

 ment of the specific identity of an aecial and telial stage on dif- 

 ferent hosts. While the technique necessary to secure infection 

 is in itself simple the knowledge of the proper trial host to use is 

 hard to obtain. Field studies on the association of hosts have 

 been the most fruitful source of information but such studies, 

 owing to the geographical location of many unconnected forms, 

 often require a greater outlay of time and money than is available. 

 The study of the morphological peculiarities of different spore 

 forms has been of great assistance as an indication of probable 

 relationships. Certain structural parallelisms often exist be- 

 tween the spore forms found on the two alternate hosts of a 

 heteroecious species ; others are found between species of Uromy- 

 ces and Puccinia; and between the teliospores of long-cyle and 

 short-cycle forms." 



Following a discussion of this paper, Dr. J. C. Arthur spoke 

 on "The Species Question among the Rusts." 



Prof. Arthur furnished the following abstract: "The history 

 of the application of names to the rusts was traced from the es- 

 tablishment of the genus Puccinia for a cedar rust by the pre- 

 Linnaean botanist Micheli to the present time. The short- 

 cycled forms, like Puccinia Xanthii, having only one spore-form, 

 have never presented special difficulties. When DeBary in 1865 

 compelled attention to heteroecism in the long-cycle forms con- 

 fusion and uncertainty began in the application of names, both 

 as to genera and species. It has been, and is still largely custo- 

 mary to refer aecial forms having the telia unknown to form- 

 genera, rather than to the true genus, even in cases where there 

 is no question of relationship. The first systematist to break 



