P R E F A C E 



This Office has tor some time had in contemplation a distribution of 

 its duplicate material to the various State agricultural experiment 

 stations, and now offers to them and other interested workers such 

 specimens as they may select from the list which follows. It is greatly 

 to be regretted that all species represented in this list are not in sufficient 

 quantity to permit the distribution to be made to the experiment 

 stations at least in uniform sets. 



Each State agricultural experiment station is invited to compile its 

 own set and to select from this list fifty specimens, which we will for- 

 ward on request, but if preferred the selection will be made here. All 

 specimens desired over fifty may be considered as in exchange. Accounts 

 will be opened with any station so that it may avail itself at once of 

 this material, even if it is not yet in position to send the exchanges for 

 specimens selected in excess of the fifty furnished free. Experiment 

 station workers will be enabled by this means to add to their reference 

 collections with but slight expense and trouble. There are. of course, 

 many things common in certain parts of the country which are either 

 rare or do not occur in other parts. We would like to get all kinds of 

 material, whether common or not. Aid is solicited toward making 

 thi> exchange a success. 



In establishing this exchange it is desired to extend its benefits not 

 only to experiment station workers, but to specialists and all who are 

 interested in the study of fungi from the economic standpoint. 



The arrangement proposed is to exchange specimen for specimen 

 when those offered are well preserved, of good quality, in abundant 

 quantity, and authentically determined, labeled, and already placed in 

 narcological envelopes. 



In regard to exchanges for undetermined specimens and material in 

 bulk requiring preparation for herbarium use. arrangements will be 

 made by correspondence. 



The attention of specialists is called to the desirability of having 

 type specimens of at least all American species deposited in the herba- 

 rium of this Office, where they will always be accessible to those inter- 

 ested. 



Address all correspondence to Mycological Exchange, Bureau of 

 Plant Industry. Department of Agriculture. Washington. D. C. 



Albert F. Woods. 



Pathologist and Physiologist. 



Office of the Pathologist and Physiologist. 



Washington, P. C. October % 1901. 



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