PREFACE. 



The bulletin submitted herewith presents the results of the work 

 up to the present time on the problems of mushroom culture and 

 spawn making. The first publication on the subject from tlie stand- 

 point of pure culture was Bulletin Xo. IG of the Bureau of Plant 

 Industry. This was followed by a Farmers' Bulletin (Xo. 201) on 

 mushroom culture, presenting the results of our work for the use of 

 the practical grower. As an outcome of the work Doctor Duggar 

 has already accomplished, spawn of pure-culture origin is now being 

 produced on a very large scale by several growers and is giving excel- 

 lent results. This method enables the grower to improve and main- 

 tain the most desirable varieties of mushrooms in the same manner as 

 is possible with other plants jDropagated from cuttings or buds. 

 Information which would enable a grower to accomplish this has not 

 been up to this time available. The general method of securing pure 

 cultures as here described will enable the experimenter to cultivate 

 spawn of other edible species of mushrooms in case it should be found 

 desirable to cultivate them. The methods described differ radically 

 from any hitherto used. They are of more general application and 

 give far better results. 



For the past three years this work has been carried on in coopera- 

 tion with the University of Missouri, Doctor Duggar having left the 

 Department to accept the professorship of botany in that institution. 

 We wish to express our appreciation of the facilities furnished by 

 the university for continuing this work. 



Albert F. Woods, 

 Pathologist and Physiologist. 



Office of Vegetable Pathological 

 AND Physiological Investigations, 



Washington., D, C.^ June 16., 1906. 



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