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interesting article by Mills and Baumgartner demonstrating DNA synthesis in isolated pea chloroplasts and its dependence on light or ATP.

The article by Gingold on the replication and segregation of yeast mitochondrial DNA is use- ful summary which points out that the ploidy paradox is not completely solved. That is, while many genetic data are consistent with a multicopy model of the mitochondrial genome other data, particularly from pedigrees, sug- gest a much smaller number of segregating cop- ies of the mitochondrial genome. Gingold discusses at tempts to resolve this dilemma involving random selection of molecules for replication and nucleoids as the segregating units, but it is patently clear that a totally satis- factory model encompassing all of the genetic and molecular data remains to be formulated. Gingold also considers the role of replication in controlling mitochondrial DNA transmission. There is also a useful review by Donachie on the genetics of cell division and chromosome segregation in E. coli which is particularly help- ful in view of the many similarities between E. coli and chloroplasts and mitochondria. Bryant summarizes succinctly what we currently know about plant DNA polymerases.

This reviewer feels obliged to note the absence of articles by T. Kuroiwa and C.W. Birky, Jr. from this volume. T. Kuroiwa has probably done the most extensive work of any investigator on the structure and organization of chloroplast and mitochondrial nucleoids and a summary of his work would have been most appropriate. Similarly, C.W. Birky, Jr. is cur- rently the foremost student of the population genetics of chloroplasts and mitochondria both from the theoretical and experimental stand- point and a paper by him accompanying Ging- gold's would have been very relevant. In spite of these omissions, this volume seems timely in view of all the excitement about the molecular biology of chloroplasts and mitochondria. It points out a whole class of interesting problems concerning the division and segregation of these organelles that seem to have been

bypassed by the majority of investigators in the field.

Nicholas W. GiUham

Dictionary of Plant Pathology, by P. Holli- day, Cambridge University Press, Cambridge, U.K., 1989, 369 pp., £30.

Plant pathology is a field in which numerous specific words are used for the description of diseases. Furthermore, there are numerous pathogen and disease names with some syn- onymy, which might be confusing for the new pathologist. Thus, it should be very useful to have a dictionary of phytopathological terms and pathogen names. This is the major goal of the Dictionary of Plant Pathology written by P. Holliday who is a well known plant pathologist of the Commonwealth Mycological Insti tute (CMI, UK} and author of the source-book Fungus Diseases of Tropical Crops. This dictionary was composed with the help of the Commonwealth Agricultural Bureau (CAB, UK) and CMI facilities which include an excellent bibliographical data bank specialized in agricul- ture and with a plant pathology section {Review of Plant Pathology, RPP).

Most of this plant pathology dictionary is composed of a list of almost all the phytopatho- genic fungi, viruses, bacteria and mollicutes together with some virus vectors and few nematodes. This list is organized by genera and then submitted in species, pathovars, forma speciale or subspecies when present. For each of these, a short description of the organism and the corresponding disease is given together with some selected bibliographical references. This description is clear and out- lines the main characteristics of the pathogen with adequate comments and bibliographic references. This is the main interest of this dic- tionary. Taxonomical problems specific to each of these organisms are well treated. For exam- ple, the names of fungi with a known sexual

stage (teleomorph) are listed as well as their corresponding asexual stage (anamorph) and cross references supply the link between these two forms. With viruses, a particular effort has been made to list all the known phytopatho- genic viruses with the description of most of their host plants when possible. Among bacte- ria, only the main phytopathogenic bacteria have been selected for this dictionary but it covers all the most significant bacterial plant diseases. This dictionary also includes disease names which are described with the reference of their causal pathogen.

The last part of this book is a dictionary of terms used in plant pathology and is more controversial as some of the definitions are not fully accepted by all plant pathologists. In this respect, P. Holliday has been guided by own opinions and those of the British Society for Plant Pathology which edited a guide for these terms in 1973. Alternative definitions or uses are sometimes given, but not always. For exam- ple, the term virulence is defined by the observ- able effects of a pathogen on its host and their different degrees, i.e. the extent of the damage caused during the infection on a susceptible host. But the term virulence is also used to refer to the ability of a pathogen to cause the disease on a resistant host, in opposition to avi- rulence which is the inability to attack such a resistant host. This last definition refers to the gene-for-gene relationship which is a very common situation found in different diseases and widely used. Thus the definition(s) selected for the dictionary should have pointed out the different uses of this term. Nevertheless, many other definitions provide good introduction to different aspects of plant pathology. In particu- lar, many terms used in physiological plant pathology are described and a large number of phytotoxins are listed with a selected bibliogra- phy. Plant defense reactions are less well covered which is regrettable as this field is in great progress. Finally, there are some descriptions of methods or compounds used in plant protection which will be of interest for people involved in this field.

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This dictionary includes many bibliographic references to articles published in scientific journals, abstracts of such articles (RPP) and books. The latter are unfortunately given with- out the publisher's name which makes them more complicated to find. With the exception of this small problem, the selected references are generally good articles on the subject. This aspect of the dictionary makes it an attractive bibliographical source book.

In conclusion, I think that the main interest of this dictionary, which covers all the prob- lems encountered in plant pathology, are its use as a source book on any disease or as an intro- ductory book to any aspect of plant diseases. Therefore, I think that it will be very useful for plant pathologists and advanced students in plant pathology.

Dr. Marc-Henri L e brun

Biochemistry of Photosynthesis, R.P.F. Gre- gory, Third Edition. John Wiley & Sons, Chich- ester, 1989, 257 pp., £21.95

During the last decade, many important developments have taken place in photosyn- thesis research. These have resulted in a pic- ture of the mechanism of the photosynthetic processes and of the structures in which these processes take place which is vastly more detailed than one might have expected only a few years ago. Studies by protein chemists and molecular biologists and X-ray diffraction ana- lysis of the bacterial reaction center have yielded increasingly detailed information on the structure and function of the photosynthe- tic membrane, while the application of advanced optical methods has provided a wealth of information on the primary photosyn- thetic reactants and their interactions.

Comparison of the present edition of Biochemistry of Photosynthesis with the pre- vious one, published in 1977, illustrates the impressive advances made during the intervening period. Not only was the book rear-