NA TURE 



421 



THURSDAY, JUNE 9, 1910. 



HANDBOOKS ON THE FRESH-WATER FAUNA 

 OF GERMANY. 



Die Susswasserfauna Deutschlands, eine Exkursions- 

 fautia. Herausgegeben von Prof. Brauer (Ber- 

 lin), i., Mammalia, Aves, Reptilia, Amphibia, 

 Pisces, by P. Matschie, A. Reichenow, G. Tornier, 

 P. Pappenheim. Pp. iv + 206; 173 figs. Price 5 

 marks. iii. and iv., Coleoptera, by E. Reitter. 

 Pp. 235; loi figs. Price 5 marks, v. and vi., 

 Trichoptera, by G. Ulmer. Pp. 326; 467 figs. 

 Price 6.50 marks. vii., CoUembola, Neuroptera, 

 Hymenoptera, Rhynchota, by R. and H. Heymons 

 and Th. Kuhlgatz. Pp. 112; in figs. Price 2.40 

 marks, viii., Ei>})<^imerida, Plecoptera, Lepidoptera, 

 by Fr. Klapdlek and K. Griinberg. Pp. 163; 260 

 figs. Price 4 marks, ix., Odonata, by F. Ris. 

 Pp. 67; 79 figs. Price 2 marks, x., Phyllopoda, 

 by L. Keilhack. Pp. iv+112; 265 figs. Price 3 

 marks, xi., Copepoda, Ostracoda, Malacostraca, 

 by C. van Douwe, E. Neresheimer, V. Vavra, and 

 L. Keilhack. Pp. 136; 505 figs. Price 3.50 marks, 

 xii., Araneae, Acarina, and Tardigrada, by F. Dahl, 

 F. Koenike, and A. Brauer. Pp. 191 ; 280 figs. 

 Price 4 marks, xvii., Parasitische Plattwiirmer, i., 

 Trematodes, by M. Liihe. Pp. iv + 217; 188 figs. 

 Price 5 marks, xix., Mollusca, Nemertini, Bryozoa, 

 Turbellaria, Tricladida, Spongillidae, Hydrozoa, by 

 J. Thi6le, R. Hartmeyer, L. von GrafT, L. Bohmig, 

 W. Weltner, and A. Brauer. Pp. v^g; 346 figs. 

 Price 4 marks. (Jena : Gustav Fischer, 1909.) 



THE aim of the editor of these volumes has been 

 to provide a complete systematic account of the 

 fresh- water fauna of Germany. In addition to the 

 parts named above, others, on the Diptera, Oligo- 

 chaeta and Hirudinea, Rotatoria and Gastrotricha, 

 Nemathelminthes and Cestodes are promised in the 

 near future; a volume on the Protozoa is not at pre- 

 sent in preparation, but may be forthcoming later. 

 There are already other accounts which deal with 

 portions of the fresh- water fauna, the organisms 

 therein considered being selected either because they 

 are the commonest fresh-water animals or because of 

 their special interest from a biological or morpho- 

 logical point of view. But in the volumes before us 

 all the known species of each group of fresh-water 

 animals are considered; thus the worker is given the 

 means of identifying any organism he may have 

 under examination provided that it has been already 

 recorded from fresh water in Germany. Whatever 

 piece of work the fresh-water naturalist may desire 

 to undertake, whether it be the study of the life- 

 history of certain animals, their distribution, their 

 behaviour under different conditions of environment, 

 or whether it be the intensive study of the fauna of 

 one pond or the more general study of the fauna of a 

 more extended area, one of the first things necessarv 

 will be the determination of the systematic position of 

 the organisms he proposes to investigate. For the 

 first time the naturalist is provided, in this series of 

 handy volumes, each written by a specialist or group 

 NO. 2 1 19. VOL. b.;] 



of specialists, with the means of identifying his 

 specimens with the minimum of difficulty and trouble, 

 and without the necessity of cAisulting expensive 

 monographs. The descriptions and diagnoses given 

 are thoroughly trustworthy and practical ; they con- 

 tain the principal morphological characters, and short 

 biological and faunistic notes are added in many 

 cases. These handbooks are not intended to supply, 

 and do not give, lengthy anatomical or biological 

 accounts of the organisms ; their function is to enable 

 the worker who consults them to identify his material 

 as speedily as possible. To this end keys are pro- 

 vided, wherever possible, to the families, genera and 

 species, and figures, for the most part in line, are 

 given to illustrate the diagnostic characters. 



As there are no definite boundaries between ttie 

 fresh-water, terrestrial, and marine faunas, it is 

 difficult to decide whether certain animals should or 

 should not be regarded as coming within the scope 

 of these volumes. The editor has included not only 

 animals which live in or upon fresh water, but those 

 which are found on the margins of ponds, lakes, 

 streams, &c., entering into intimate association with 

 the water; others which seek the water only tem- 

 porarily have been excluded. On the whole, the 

 limits of the fresh-water fauna have been liberally 

 interpreted. In order to give a more complete 

 account, mention has been made in some cases of 

 developmental stages of organisms, although these 

 stages do not actually occur in fresh water; for in- 

 stance, the larvae — Leptocephali — of the eel are men- 

 tioned and figured. Our knowledge of some divisions 

 of the fresh-water fauna is at present in a ven.- im- 

 perfect condition ; the adult forms of many animals 

 are well known, while their younger stages are but 

 inadequately described. These volumes, which will 

 reach the hands of the majority of serious workers, 

 will fulfil the purpose, among others, of ser\-ing as a 

 record of our present knowledge, and will show the 

 lacunae which remain to be filled by future observa- 

 tions. 



Heft i. deals with the whole of the vertebrates 

 found associated with fresh water in Germany. The 

 treatment of the Amphibia may be instanced as an 

 example of the method adopted in this volume. A 

 table of the diagnostic characters of adult Urodeles 

 is given, by means of which Salamaudra maculosa, 

 Molge alpestris, palmata, cristata, and vulgaris may 

 be distinguished. In the following part, which deals 

 with the Batrachia, there are tables for the identifica- 

 tion of (i) the fully adult frogs, Hyla arborea, Bufo 

 viridis, vulgaris, and calatnites, Rana temporaria, 

 arvalis, and esculenta (three varieties). Bomhinator 

 pachypus and igneus, Pelohates fuscus, and Alytes 

 obstetricans ; (2) their spawn ; (3) the young tadpoles 

 with external gills ; and (4) older tadpoles with in- 

 ternal gills. The third table is accompanied by the 

 suggestion that it should be used only in case of those 

 specimens which die in this comparatively early stage 

 of development, and that it is preferable, wherever 

 possible, to keep the tadpoles alive until the fourth 

 table can be applied, with more certaint}-, to their 

 identification. These four tables are illustrated bv 



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