498 Dansk Botanisk Arkiv, Bd. 3. Nr. 1. 



I should also like to thank the American algologist Dr. M. A. 

 Howe who sent me large collections of West Indian algæ, which 

 have been of great use to me for purposes of comparison, con- 

 cerning many doubtful forms. 



Then I owe a debt of gratitude to the late Prof. W. G. Far- 

 low for his valuable assistance and for the interest he always 

 showed in my work, and to the late F. S. Collins, who sent 

 me much valuable material of West Indian algæ, and through 

 his extensive knowledge of the American algal flora supplied me 

 with much useful information. 



Moreover I am highly indebted to Prof. C. Lindman of the 

 Riksmuseum, Stockholm, and Prof. N. Svedelius of the Bota- 

 nical Museum, Upsala, for the loan of algæ to compare with 

 my collections. Likewise I am sincerely grateful to the Professors 

 MuRBECK and Nordstedt for their courtesy in giving me access 

 to Agardh's Herbarium in Lund. 



Finally I seize the opportunity to thank my colleague. Prof. 

 Rosenvinge, to whom I owe much important imformation and 

 who, as editor of Dansk Botanisk Arkiv, has assisted with the 

 reading of the proof-sheets. 



Mr. OvE Rostrup has helped me with most of the drawings, 

 and my best thanks are due to him for the trouble he has taken. 



Then I should hke to thank most cordially Mr. A. D. Cotton 

 of Kew, who has done me the great service of reading my proof- 

 sheets, by which those errors, which easily arise when a foreigner 

 has to write a language not his own, have been as far as possible 

 put right. 



Finally 1 want especially to thank the Trustees of the Carls- 

 berg Foundation, not only for the continued grant for the re- 

 production of the many drawings, but particularly for the special 

 grant for the printing of the last part which otherwise must have 

 waited, owing to the high cost of printing at present. 



With this I take leave of those beautiful small islands where 

 so many of my thoughts and so much of my work have been 

 centred for so many years, and the parting is the more painful 

 since the tie, which bound the islands to my native land, has 

 been severed. 



