THE DEVELOPMENT OF LEPIOTA CRISTATA AND 



L. SEMINUDA 



Geo. F. Atkinson 



Cornell University 

 (with plates 21-26) 



Introduction 



The development of the fruit body in the Agaricaceae, with 

 special reference to the differentiation and organization of the 

 principal parts, has been studied in comparatively few forms. 

 Approximately sixty species representing some twenty genera 

 have been examined. More than three fourths of these species 

 were studied during a comparatively early period, from 1842 to 

 1889, when the methods of technique employed were less satis- 

 factory than at the present time. Consequently many of the 

 species studied during that period were more or less imperfectly 

 examined. During the last decade less than a dozen species have 

 been studied. Owing to progress in technique, this study has been 

 correspondingly intensified and more satisfactory results have 

 been obtained. 



The unfolding of the parts of the fruit body, after their organiza- 

 tion in the young basidiocarp, has been studied in a large number 

 of species. But this phase of the work relates almost wholly to 

 macroscopic observations on the gross morphology. These studies 

 of the grosser features in development cover a period of about 

 one hundred years, beginning early in the nineteenth century, when 

 the science of mycology began to emerge from its mystic age. 

 These morphological features have been the chief elements on 

 which all our taxonomic systems of the fungi have been based. 

 We continue to shuffle them into new patterns, or dies, for the 

 rearrangement of present, or the manufacture of new genera, 

 without a clear understanding, in many instances, of their real 

 taxonomic significance. 



A study of the origin, differentiation, and organization of the 

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