INDEX DESMIDIACEARUM. 105 



besondere Leistungen." The latter deals with means of attach- 

 ment by hairs, mucilage, &c. ; mechanisms of movement, whether 

 passive, like hairs or membranous expansions, or active, like hygro- 

 scopic contractions; means for receiving stimuli (e.tf. the hairs on 

 the leaves of TJionaa) and tissues along which the stimulus may be 

 supposed to travel. The chapter on the structure and functions of 

 the typical plant-cell has been extended ; and the two sections 

 dealing with normal and abnormal thickening have been united 

 under a common head, "Secondary Growth in Thickness," so that 

 the number of sections (twelve) remains the same as in the edition 

 of 1884. The majority of the additional figures are original. 



A. B. R. 



Index Desmldiacearum citatiunibus locupletissimus atque Bibliographia. 

 Auctore C. F. 0, Nordstedt. Berolini : Fratres Borntraeger. 

 1896. 310 Seiten. 4°. Preis 20 mark. 



The author treats of his subject under five sections. The first 

 of these is the bibliography, and, including the two pages of ad- 

 denda constituting the third section, it may be said to be complete 

 up to about September, 1896, being in fulness and general accuracy 

 of reference much superior to previously published lists of Desmid 

 literature. The second section, the Index, consists of an alpha- 

 betically arranged list of the generic and specific names of Desmids 

 and some doubtful structures which have been described as such. 

 Under each specific name is a chronological series of records of 

 that species, varieties and changes of generic position each being 

 marked by special type, and the nature of each record is indicated 

 by means of contractions, a list of which is given in the Preface. 

 Thus, to take an example, on p. 10, under "dissilieiis," is found the 

 reference "phzf 57 — HoJ'in. Fortpl. p. 35 t. 1 f. 5-8," indicating 

 that Hofmeister's paper was published in 1857 with some physio- 

 logical observations, description of zygospores, and figures. The 

 change of type on the subsequent recording of a variety serves its 

 purpose very well, but fails to do so in those instances in which 

 more than one variety has been given the same name by different 

 authors. Thus on p. 37, under "acerosuvi," there are two varieties 

 with the name " eloiufatiaii," and as only one of these (the first 

 mentioned one) is in the usual strong type, the other is liable to 

 be overlooked. This change of type is accompanied by a change of 

 the authority from the original describer to the recorder ; thus on 

 p. 87, under '^ crassion," is found the \a,Y. sciobiculatnin viith the 

 following authorities,— "Lund.," "Nordst.," " Wolle," "Lagerh.," 

 and " Toni." From this one might be led to infer that each of 

 the above described a var. scrobicidatum, and that it was a similar 

 case to that mentioned as occurring on p. 37. 



The author's suggestions, short notes, and cross-references add 

 considerably to the usefulness of the Index ; and the last section 

 of the work, consisting of an alphabetical enumeration of the 

 genera with their contained specific names, will also be found 

 extremely useful for purposes of reference. 



