FOREWORD 



Advancement in our knowledge of the fresh-water algae in general 

 and of algal distribution in particular stems from many different kinds 

 of publicati^ons, running the gamut from comprehensive and mono- 

 graphic volumes to modest reports of local lists. It will continue to be 

 necessary for many persons to collect and identify algae, to describe 

 and report them from all sorts of habitats throughout the world, and 

 to cultivate them under various laboratory conditions. Only in this 

 way may our inquiries into the taxonomy, morphology, physiology, 

 ecology, and genetics of the algae make appreciable progress. 



Literature on the algae has accumulated with such rapidity during 

 the last three or four decades that it is necessary now and then to 

 assemble the known data in a form more readily available to students 

 of this plant group. The number of papers dealing directly or indi- 

 rectly with Illinois algae is very large, as indicated in the bibli- 

 ography at the end of this book. The first step in summarizing our 

 knowledge to date of the algae of Illinois is largely bibliographic, 

 involving an examination into such matters as distribution, syn- 

 onymy, and classification. The "Catalog of Illinois Algae" represents 

 this first step. 



Such a venture is by no means an easy task, and perhaps complete- 

 ness is scarcely to be attained. Professor Britton has, however, at- 

 tacked the problem in a thorough-going manner, using both pub- 

 lished and unpublished data — many of them his own — for the present 

 summary. He will welcome corrections and additions to the Catalog. 



The department of botany at Northwestern University plans to 

 extend this summary survey in subsequent reports to include descrip- 

 tions, keys, illustrations, and habitat analysis for the algal groups 

 growing in Illinois. It is hoped that such a series will stimulate inter- 

 est in and continued investigation of these aquatic plants. 



I L. H. Tiffany 



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