Ronald Chase

Behavior and its Neural Control in Gastropod Molluscs

Oxford University Press, New York, 2002. List Price $85, £55. Hardback, xx + 314 pages. ISBN 0-19-511314-4

The use of molluscs as models for the study of the nervous system has, since the use of squid giant axons, been one of the principal 'justifications' for the study of the phylum. Gastropod behaviour is, of course, worthy of study in its own right, and readers should not assume from the blurb on the cover that this book is only for neurologists seeking a simpler model for understanding the mammalian brain. This is two valuable books in one volume: the behaviour of a large range of gastropods, and the neural basis of gastropod behaviour. The behaviour sections are biased towards those which can be mapped on to a neural basis, so areas such as coloration receive little mention. Workers on one taxon can profit by seeing work on 'their' animal described alongside a description of the situation in other gastropods. Neurologists will obviously benefit from reading this book, but so too will behavioural ecologists and ethologists.

The book is laid out in ten chapters. After initial chapters reviewing the gastropod groups and the organisation of the central nervous system ganglia in different groups, there are chapters on sensory systems, and on muscles and the peripheral nervous system, including peripheral reflexes. The remaining chapters each start with behaviour and follow on to the neural bases. Chapter 5 deals with respiration, circulation and water regulation, chapter 6 with the regulation of crawling and swimming. This includes a section on taxes and the interaction of sensory inputs, for example Clione's changing geotaxis dependent on water temperature. The chapter on feeding includes a valuable comparative review of feeding habits, food finding, and, of course, central pattern generators controlling buccal movements, and their modulation, and includes studies of operant conditioning in Aplysia. The chapter on reproduction again demonstrates a balanced coverage of reproductive strategies and the nervous control of courtship, copulation and egg-laying. Chapter nine deals with defensive strategies - both withdrawal reflexes (and habituation and general sensitisation), and chemical defences, and the last chapter with temporal organisation - seasonal and daily cycles, arousal, and the hierarchical organisation of behaviours. Within each chapter section, one or two key researches are well described and critically evaluated, with some extensions from other researches.

There are three indices- subject, taxonomic and neuronal. The taxonomic index reveals the range of gastropods included, while the neuronal index is a useful innovation. The subject index is rather brief - arousal, homing and hibernation are not indexed, although they are covered in the text. However, the chapters are well laid out so that there is little difficulty finding most material unless it falls into more than one possible category - as for example the sexual arousal of Helix prompted by food, which is in the chapter on temporal organisation, not feeding or reproduction.

Chase makes clear in the introduction that this book is intended to be useful -and it is. The author picks modern examples, so that this book is an excellent review. However, there is also sufficient background to make the work accessible to undergraduate students. Here is a clearly written, well researched compendium of modern research which should be in every university library and on the bookshelves of all invertebrate neurologists and behaviourists.

Bill Bailey

S. M. Walters & E. A. Stow

Darwin's Mentor - John Stevens Henslow, 1796-1861

Cambridge University Press, 2001. £40. Hardback, xx + 338 pages. 50 b+w and 14 colour plates. ISBN 0 521 591465.

Henslow is well known as the Cambridge Professor of Botany who influenced Darwinís career more than any other, and recommended him as naturalist on the 'Beagle'. He also recommended that Darwin take with him the first volume of Lyell's Principles of Geology ("but on no account to accept the views therein advocated"). In this book, we discover Henslow as a young entomologist and shell collector (the discoverer of Pisidium henslowanum), a geologist (he was Professor of Mineralogy before the chair of Botany became available), a founder of the Cambridge Philosophical Society, and responsible for the removal of the Universityís old Botanic Garden to its present larger and less enclosed site. The book's numerous quotations do much to evoke the place and time of the characters. Max Walters, a former Director of the Botanic Gardens, includes an account concerning a problem with jackdaws that inhabited the buildings surrounding the Old Botanic Garden removing the wooden labels from the collection: from one chimney shaft, eighteen dozen labels were removed! Henslow's charm as a teacher sprang in no small part from the courteous attention that he showed equally to the youngest student as to a distinguished colleague. His students commented on the clarity of his lectures, the admirable large scale illustrations, and the practical demonstrations and field excursions. Henslow also emerges as an educational reformer (both for Cambridge botany, and later as examiner for London University), and as a liberal-minded and philanthropic Anglican priest, working to revive the spirit of the rural Suffolk village of Hitcham where he was Rector. Although he was a reformer rather than a discoverer, his studies of Primulas and hybrid Digitalis and Potentilla inclined him to accept Darwin's theory at the level of genera. Henslow's involvement with Hitcham and the Ipswich museum so preoccupied him that his stay in Cambridge was reduced to five weeks teaching each year, and, from his former pupil's collections, he selected only two Opuntia species from Galapagos and the Keeling (Cocos) Isles flora for study. Thanks to Anne Stow's expertise as scientific librarian at Cambridge, this biography has brought forward much previously unpublished material. The book includes genealogical tables, a chronology, brief biographies of persons mentioned, and lists of eponymous taxa, local botanical records and Henslow's works. The authors are to be congratulated on producing a book that is a thoroughly enjoyable read, and it will be a useful addition to any library's collection of Darwiniana.

Elizabeth Platts and Bill Bailey