VI DESMIDS OF THE UNITED STATES. 



I'liitnl States. Every succeeding year up to l*s.'J, I have recorded in 

 the same journal the results of my observations upon this interesting 

 class of American flora ; what my success has been, may he interred 

 from the fact that I have in my herbarium nearly five hundred well 

 authenticated species and varieties of American Desmids. 



Only the great pleasure I derived from collecting, and studying 

 the life-history of this heretofore neglected class of plant-, enabled 

 me to make light of, and to overcome, the serious obstacles I met 

 with at the outset of my labors. There were no home correspondent- 

 with whom to co-operate and no accessible good works to guide me 

 in my researches over this almost wholly unexplored Held. My first 

 encouragement came from abroad. The late Dr. L. Rabenhorst, of 

 Mei-.-en, 1'rus-ia, and the late Alexander Braun, of Berlin, sent me 

 many valuable communications, and to the former particularly, I 

 furnished many sets of mounted specimens of our Algte for his serial 

 of decades of J ti/n l-].rx'x-<-t'. I am particularly indebted, however. 

 to Dr. Otto Norclstedt, of the University of Lund, Sweden, for his 

 kindness in determining the identity of certain American specie- 

 discovered by me with those already known in Europe; and also in 

 confirming my impressions concerning the restriction of others solely 

 to the United State-. 



My grateful acknowledgments are also due for valuable notes and 

 papers, to Dr. V. 15. Wittrock, of the Scientific Academy of Stock- 

 holm; N. \Ville, of Christiana, Norway ; F. Hauck, Trieste; Dr. .1. 

 Rostafinski, Cracow; G. Lagerheim, Stockholm, and others. 



Meanwhile, the subject had awakened interest in various parts of 

 the United States, and specimens began to come in from places it 

 would have been impossible for me to have visited. Among those 

 to whom I am particularly indebted for favors of this kind, are: Mr. 

 H. W. Ravenel, Aiken, S. C., who during the past eight or more 

 year-, has sent me many interesting specimens, from his own State, 

 (ieorgia and Florida; ('apt. J. Donnell Smith, Baltimore, Md., who, 

 in I.ST.S and isy.i, sent me over seven hundred specimens of fresh- 

 water Afffce gathered in Florida; in his collections the Desmids were 

 not numerous, but they included specimens not found elsewhere; 

 Mr. F. H. Hosford, assisted by Mr. C. G. Pringle, Charlotte, Vt.. 

 whose collections were copious in northern Vermont; and Miss 

 Eloise Butler, Minneapolis, Minn., who was a most successful col- 

 lector of Desmids; I am indebted to her for all the species in the 

 li-t which are assigned to Minneapoli-. My acknowledgments would 

 not be complete did I omit to mention the practical interest taken 

 in my labors by the Rev. H. D. Kitchel, and his son, Mr. H. S. 

 Kitchel. 



In the descriptive parts, I have abbreviated the name of tin- dis- 

 coverer of each plant, the reader being referred, for additional infor- 

 mation, to the appended list of names alphabetically arranged with 

 their abbreviations, and with the title of the books consulted in the 

 compilation of this work. 



