- Email: [email protected]
1 ‘bacillariophyceae’ 1. Teil: Naviculaceae
402
clumsy opening remarks about tundra vegetation (p. 85), only a few of many examples, might have been rectified before going to press. The heading on p. 49 should not have escaped unnoticed. On p.7, notwithstanding her prefatory comments, Dr Sprent indicates that her purpose was to "explore .... variations" (in the steps of the cycle). I believe she has approached that goal more fully than summarising "the current situation", interpreting the latter to mean knowledge of the N cycle in all its aspects. Prospective readers are likely to find the result useful to a degree in both respects even in face of the limitations I have attempted to indicate. J.S. BUNT
56 Cutten Street Bingil Bay Queensland 4854 Australia
EUROPEAN DIATOMS
Siisswasserflora von Mitteleuropa 2/1 'Bacillariophyceae' 1. Teil: Naviculaceae, by K. Krammer and H. Lange-Bertalot. Gustav Fischer Verlag, Stuttgart, New York, 1986, XVI + 876 pp., DM. 220,00, ISBN: 3-437-30403-8. The delimitation of the Bacillariophyceae or diatoms has never given any trouble; this cannot be said of the delimitation of the taxa on the species level. The introduction of electron microscopy has enabled many former taxonomical problems to be solved, but in spite of the fact that many species can now be defined more precisely many questions still remain. The progress in diatom taxonomy can easily be deduced from the fact that all diatoms in the first edition of the "Siisswasserflora von Mitteleuropa" could be comprised in one volume with 187 pages (H. von Sch6nfeldt, Die Sfisswasserflora Deutschlands, Osterreichs und der Schweiz Heft 10. Bacillariales (Diatomeae), 1913). In the present edition 3 sizeable volumes are needed. The present volume deals only with one family, the Naviculaceae, with 22 genera and 535 species of which 227 belong to Navicula, 74 to Cymbella and 55 to Pinnularia. The introductory general chapter is very thorough and critical. The terminology is well-defined in a glossary, to which a table is added giving the English, French and Latin translations for the terms used, so that the work also can be used by investigators which are not in command of the German language. The terms used for light-microscopical and for electron-microscopical concepts are strictly separated in order to prevent confusion. All structures and phenomena are extensively described, such as: the struc-
403
ture and the contents of the cell wall; the morphology of the cell wall (form types, structural types, pores, raphe, girdle, other surface structures, etc. ); sexual and asexual reproduction; euplasmatic structures; morphogenesis of the cell wall; locomotion, and distribution and ecology. The general part is concluded by a methodological chapter on the collection methods, and the preparation of the material for the various analytical treatments. The subchapter on distribution and ecology is short but clear. Most species appear to have a world-wide distribution, or to be restricted to certain climatic zones. The authors point out that the distributions of these species cannot be compared with similar distributions of angiosperms, because of their very easy means of dispersal. The authors consider the progress of diatom ecology up to now as "disappointing". They point out that the often-used pH data are unreliable because of their large fluctuations, and advocate the measurement of alkalinity. The measurement of electrolyte content (conductivity) is regarded as acceptable, but at the same time it is remarked that there is often little relation between the occurrence of diatoms and such data, because the microhabitats of the diatoms are rarely actually sampled. Another frequently applied parameter, oxygen saturation, also needs to be dealt with cautiously, and the authors warn explicitly for the use of physiological characteristics, as e.g. facultative or obligatory nitrogen heterotrophy, which is not easy to determine, and is of course only known for a very few species. Most attention is given by the authors to the tolerance of diatoms to organic pollution, an approach in limnology which nowadays seems only of interest to Germans. The systematic treatment seems sound; the authors outline in an excellent way the systematic concept that they apply, and which is quite conservative. The descriptions of the genera and species are clear; synonyms are given. If there is a possibility of confusion with other species, or when there are taxonomic problems, these are mentioned. In one place in the book (p. 257) this leads to a remarkable situation, as the eighth species of the genus Anemoeoneis is given as Brachysira aponina. The authors purposely do not make the transfer of this species to the genus Anomoeoneis, because they want to settle systematic problems in a wider context. However, they do not seem to recognize the genus Brachysira. The volume is illustrated with 206 whole-page plates showing light-microscopical as well as electron microscopical details. The use of a good quality paper is a welcome improvement to the situation in some of the previous volumes. C. DEN HARTOG
Universiteit van Nijmegen Laboratorium voor Aquatische Oecologie Toernooiveld, 6525 ED Nijmegen The Netherlands
clumsy opening remarks about tundra vegetation (p. 85), only a few of many examples, might have been rectified before going to press. The heading on p. 49 should not have escaped unnoticed. On p.7, notwithstanding her prefatory comments, Dr Sprent indicates that her purpose was to "explore .... variations" (in the steps of the cycle). I believe she has approached that goal more fully than summarising "the current situation", interpreting the latter to mean knowledge of the N cycle in all its aspects. Prospective readers are likely to find the result useful to a degree in both respects even in face of the limitations I have attempted to indicate. J.S. BUNT
56 Cutten Street Bingil Bay Queensland 4854 Australia
EUROPEAN DIATOMS
Siisswasserflora von Mitteleuropa 2/1 'Bacillariophyceae' 1. Teil: Naviculaceae, by K. Krammer and H. Lange-Bertalot. Gustav Fischer Verlag, Stuttgart, New York, 1986, XVI + 876 pp., DM. 220,00, ISBN: 3-437-30403-8. The delimitation of the Bacillariophyceae or diatoms has never given any trouble; this cannot be said of the delimitation of the taxa on the species level. The introduction of electron microscopy has enabled many former taxonomical problems to be solved, but in spite of the fact that many species can now be defined more precisely many questions still remain. The progress in diatom taxonomy can easily be deduced from the fact that all diatoms in the first edition of the "Siisswasserflora von Mitteleuropa" could be comprised in one volume with 187 pages (H. von Sch6nfeldt, Die Sfisswasserflora Deutschlands, Osterreichs und der Schweiz Heft 10. Bacillariales (Diatomeae), 1913). In the present edition 3 sizeable volumes are needed. The present volume deals only with one family, the Naviculaceae, with 22 genera and 535 species of which 227 belong to Navicula, 74 to Cymbella and 55 to Pinnularia. The introductory general chapter is very thorough and critical. The terminology is well-defined in a glossary, to which a table is added giving the English, French and Latin translations for the terms used, so that the work also can be used by investigators which are not in command of the German language. The terms used for light-microscopical and for electron-microscopical concepts are strictly separated in order to prevent confusion. All structures and phenomena are extensively described, such as: the struc-
403
ture and the contents of the cell wall; the morphology of the cell wall (form types, structural types, pores, raphe, girdle, other surface structures, etc. ); sexual and asexual reproduction; euplasmatic structures; morphogenesis of the cell wall; locomotion, and distribution and ecology. The general part is concluded by a methodological chapter on the collection methods, and the preparation of the material for the various analytical treatments. The subchapter on distribution and ecology is short but clear. Most species appear to have a world-wide distribution, or to be restricted to certain climatic zones. The authors point out that the distributions of these species cannot be compared with similar distributions of angiosperms, because of their very easy means of dispersal. The authors consider the progress of diatom ecology up to now as "disappointing". They point out that the often-used pH data are unreliable because of their large fluctuations, and advocate the measurement of alkalinity. The measurement of electrolyte content (conductivity) is regarded as acceptable, but at the same time it is remarked that there is often little relation between the occurrence of diatoms and such data, because the microhabitats of the diatoms are rarely actually sampled. Another frequently applied parameter, oxygen saturation, also needs to be dealt with cautiously, and the authors warn explicitly for the use of physiological characteristics, as e.g. facultative or obligatory nitrogen heterotrophy, which is not easy to determine, and is of course only known for a very few species. Most attention is given by the authors to the tolerance of diatoms to organic pollution, an approach in limnology which nowadays seems only of interest to Germans. The systematic treatment seems sound; the authors outline in an excellent way the systematic concept that they apply, and which is quite conservative. The descriptions of the genera and species are clear; synonyms are given. If there is a possibility of confusion with other species, or when there are taxonomic problems, these are mentioned. In one place in the book (p. 257) this leads to a remarkable situation, as the eighth species of the genus Anemoeoneis is given as Brachysira aponina. The authors purposely do not make the transfer of this species to the genus Anomoeoneis, because they want to settle systematic problems in a wider context. However, they do not seem to recognize the genus Brachysira. The volume is illustrated with 206 whole-page plates showing light-microscopical as well as electron microscopical details. The use of a good quality paper is a welcome improvement to the situation in some of the previous volumes. C. DEN HARTOG
Universiteit van Nijmegen Laboratorium voor Aquatische Oecologie Toernooiveld, 6525 ED Nijmegen The Netherlands