BRYOLOGY 



By WILLIAM C. STEERE 

 Stanford University 



The last hundred years have brought substantial and noteworthy progress 

 to the field of bryology; in fact, the century just past may appropriately be 

 termed the golden age of systematic and floristic studies on bryophytes, since 

 in these years the number of known species increased tenfold. This account of 

 progress opens with especial suitability with the year 1851, because that marks 

 the date of completion and of publication of the last attempt to bring together, 

 in a single work, descriptions of all mosses of the whole world (C. Miiller, 

 1848-1851). In this great work Miiller described fewer than 2,400 species of 

 Musci and only 25 species of Sphagnum. The great contemporary treatment 

 of the world's hepatics (Gottsche, Lindenberg and Nees, 1844-1847), completed 

 very shortly before the opening of the century under consideration here, brought 

 together for the first time descriptions of some 1,600 species. This was the age 

 of descriptive botany — systematic, morphologic, and anatomic. The field of plant 

 physiology was still primitive and with little application to bryophytes. Before 

 Darwin and Mendel such fields as phylogeny, genetics, cytogenetics, and cyto- 

 taxonomy — as well as experimental morphology and biochemical physiology — 

 naturallj^ did not exist. 



The task of summarizing the development of the field of bryology during 

 the past century, in all its ramifications, is by no means an easy one, because 

 of the extensive and unorganized literature. Bryology, aside from its purely 

 systematic and floristic aspects, has been established as a field so recently, and 

 by so few workers, that no over-all summaries or compendia have yet been pro- 

 duced, with the outstanding exception of the Manual of Bryology, an excellent 

 symposium edited by Verdoorn (1932). The widely scattered nature of the 

 literature of br^^ology, falling rather sharply into specialized categories, makes 

 it difficult indeed for those in other fields — and for bryologists themselves — to 

 gain any general insight into the philosophies, the outlooks, and the problems of 

 bryology. In the limited space available for this review, the most effective ap- 

 proach seems to be to outline briefly the modern developments in various aspects 

 of bryology and to furnish key citations to relatively recent publications, through 

 which interested persons may gain access to the fuller literature of any special 

 topic. The selection of titles for inclusion in the Bibliography largely empha- 

 sizes recency rather than size or general importance of the contribution, since 

 a sometimes relatively small recent paper will not only supply references to 

 the important earlier literature but may also furnish supplementary informa- 

 tion. Although the rigorous selection practiced here prevents the Bibliography 

 from exceeding all bounds, it also calls for the author's apology to many bryolo- 

 gists whose important works have been excluded. 



Because of the lack of comprehensive surveys of the literature of bryology 



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