BOOK REVIEWS 

 Tilden's ''The Algae and their Life Relations"^ 



Professor Tilden, who is well known to students of the algae 

 through her monograph of the "Myxophyceae of North America 

 and Adjacent Parts" and other important works, has recently 

 published her magnum opus under the above title. It is designed 

 especially to give students an outline of the fundamentals of 

 phycology, and the term "algae" is interpreted in its broadest 

 sense, including the Blue-greens (Cyanophyceae) and Yellow- 

 greens fChrysophyceae), as well as the Greens, the Browns, and 

 the Reds. A geological time-table, showing the supposed se- 

 quence of the larger groups of algae, with the Cyanophyceae 

 the oldest (early ArchaeozoicJ. and the Chlorophyceae the latest 

 (Proterozoicj , and showing also the sequence of the higher 

 groups of plants, occupies the frontispiece. The author con- 

 siders the development of the main lines to have been, for the 

 most part, parallel rather than branching and tree-like. 



A general work of this kind can hardly aim to be complete 

 in its references to genera and species, but most of the larger 

 and more important genera are briefly described and many of 

 them are illustrated. While the author appears to be usually 

 accurate and up to date in discussing the general morphology 

 and cytology of the algae, the reader may be a bit surprised to 

 find her writing of Caulerpa "method of reproduction un- 

 known," when the presence of swarmers in Caulerpa was an- 

 nounced by Dostal as early as 1928. This was confirmed by 

 Schussnig in 1929, by Ernst in 1931, and by Iyengar in 1933, 

 the later observers noting two sizes of the supposed gametes. 



The bibliography, though occupying 23 pages of small print 

 and seemingly very full, shows several curious lacunae. Thus 

 J. Agardh, whose books and papers on the algae include more 

 than 40 titles and who is one of foremost writers in this field, 

 is wholly missing in the list, and his distinguished father, C. 

 Agardh, is represented only by the first part of the first volume 

 of his classic "Species Algarum." Also, the names of Montagne, 

 Schmitz, and Foslie, each with numerous important papers to 

 his credit, are among the missing. Bornet & Thuret are repre- 



^ Tilden, Josephine E. The algae and their life relations. 8-vo. Pp. i-xii 

 -i-1-550./. 1-257 +pl. 1-9. 1935. The University of Minnesota Press, Minne- 

 apolis. Price $5.00. 



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