—49— 



the two years occupied in this fascinating research. They represent the result 

 of work on upward of 230 species, or forms considered as such, 176 of which 

 are described, while the rest lie in the herbaria, bearing so far only noinnia 

 niida. It is a joy to look upon such a masterpiece of manual skill and un- 

 tiring scientific devotion, a model both in its mechanical aspect, and the sci- 

 entific spirit which breathes from all its pages. It was "crowned" by the 

 Academ}^ in whose Memoirs it was first published, an honor which it well 

 deserves. 



According to the author the leaf structure furnishes the ground for 

 separating this group into four tribes comprising nine genera. An excellent 

 conspectus of characters is given at the close of the detailed discussions, 

 summarizing the author's anatomical observations. 



Mr. Cardot, in his introductory remarks, sums up the points which his 

 researches have tended to establish as follows: 



*• 1. A more e.xact knowledge of the anatomical structure of the leaf, 

 heretofore described by all authors in a very inadequate manner. Not suffi- 

 cient emphasis was laid on the fact that, in the majority of species, the leaf 

 structure varies according to the level at which it is examined, and that in a 

 manner constant for a given species. In this fact will be found good indica- 

 tions for the delimitation of species. 



" 2. Confirmation of the theory of Lindberg, who considered the leaf of 

 the Le 1(1 oby inns to be formed almost entirely of a very much dilated costa, 

 while the majority of authors claim, wrongly, that it is deprived of costa. 



"3. Indications, from the morphological and anatomical investigations, 

 of characters which relate the Leitcobryaceae on the one hand to the Dioan- 

 aceat', on the other hand to the genus Syrr/iopochvi. 



" 4. A more satisfactory and more natural delimitation of the generic 

 groups by the aid of the anatomical structure of the leaf.'' 



/. M. Holzinger. 



The European Sphagnaceae. 

 By E. Charles Horrell, F. L. S. 



Mr. Horrell has recently issued in separate form his several papers on 

 these mosses, reprinted from the Journal of Botany, April to December, 

 1900, and repaged consecutively, making it a very serviceable handbook 

 for European students of this group. In the introduction the author gives 

 a fairly complete bibliography of the group. Pp. 5-13 contain an excellent 

 key to the species; and on pp. 39 to 41 is found a revised key to the Cuspi. 

 datu))i group. The treatment throughout is after 'Warnstorf. Of the fifty 

 species (taking no account of the numerous varieties) which are treated and 

 carefully described in this little volume, 35 are common to North America. 

 And it is partly for this reason that this work is brought to the attention of 

 American students. But the feature that commends itself most especially to 

 the writer, is the description of the method of staining and handling these 

 plants for successful study, given on pp. 3-4. The author's address is E. 

 Charles Horrell, 49 Danby Street, Peckham S. E., London. /. M. H. 



