North Pacific Coast Species of Desmarestia 



ViNNiE A. Pease, 

 University of Minnesota, Minneapolis. 



Comparatively little work has been done upon the genus Desmarestia, 

 although it is one of the most widely distributed of the marine algae, 

 several species are easily available, its structure is most interesting, its 

 method of reproduction has long been a matter of doubt, and its systematic 

 position is still unsettled. Descriptions of some of the species are given 

 in the earliest botanical works of England and the Continent; Kiitzing 

 (11) and Thuret (30) early began the study of its structure and repro- 

 duction; but the first important contribution, other than taxonomic, was 

 that by Soderstrom (28) on the anatomical structure of D. aculeata. 

 Rosenvinge (2t) and Kuckuck (10) established the method of reproduc- 

 tion, and Jonsson (8) published a scholarly article on the structure and 

 development of the thallus. Oltmanns (20) gave a brief summary of 

 what was then known of the genus, and Skottsberg (27) gave a very good 

 discussion of the Antarctic species. 



These are perhaps the most important articles dealing directly with the 

 genus. A painstaking student, with good library facilities, will find many 

 references to the genus, or to one or more of its various species, but the 

 great majority of these are taxonomic or deal with geographical distri- 

 bution ; many of them are in monographs not widely circulated ; many are 

 extracts from more general articles, and others are mere incidental ref- 

 erences. It has seemed to the writer, therefore, that it would not be an 

 unnecessary duplication of labor to take up a detailed study of the genus, 

 especially of those species found on the north Pacific coast, summarizing 

 the literature, assembling what is already known of distribution, growth 

 habit, structure, and reproduction, and adding to the work already done 

 the results of her own observations and study. The present article is 

 merely a preliminary statement to be followed within a few months by a 

 more detailed account. 



The genus Desmarestia, so named by Lamouroux (12) in honor of A. 

 G. Desmarest, a celebrated French naturalist and professor of zoology, 

 at first consisted of the S common European species, D. aculeata (L.) 

 Lamour., D. viridis (Muell.) Lamour., D. ligulata (Lightf.) Lamour., and 

 the Pacific coast D. herbacea (Turn.) Lamour. To this list, as a result 



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