BOOK REVIEWS 955

Chapters 4 and 5 are concerned with extra-retinal photoreception and colour vision. Underwood's chapter on extra-retinal photoreception is valuable in that it con- tains most of the scant information in the book dealing with invertebrates. It is an informative and topical examination of biological clocks, which have enormous potential as links between the neurology and behaviour of animals.

Colour (the prime theme of the book) with its at tendant ethological relationships comprises the remainder of the book and is, in this reviewer's opinion, the weakest part. Hailman's chapter on environmental light and coloration is of particular interest in view of the recent works on the sensory ecology of firefly flashes and deep-sea biolumi- nance. However, I found that, without Hailman's (1979) previous text, Optical Signals, it was extremely difficult to follow the text of his present work. The progression from this work to two chapters on interspecifie communication is strained and not taken full advantage of. Of regrettable absence are any papers dealing with marine habitats, environments where an organism's colour environment changes radically with depth; and again the invertebrates are sorely under-represented. Rowland's concluding chapter on behavioural contexts of coloration is, however, interesting as it examines the often over-worked roles of colour in fish communicative behaviour.

To individuals well versed in the complexities of colour and vision, Burtt 's book is a valuable contribution, albeit somewhat focused on terrestrial vertebrates. I t does, however, have limitations as a general introductory text for those members of physiology/ethology camps more permanantly wedded to their own disciplines. A broader view of animals and their visual ecologies would better serve the interests of the more generalized researcher.

JAMES FULLARD Department of Biology, University of Toronto, Erindale Campus, Mississanga, Ontario, Canada L5L 1 C6

Reference Hailman, J. P. 1979. Optical Signals. Bloomington:

Indiana University Press.

Animal Thought. By STEPHEN WALKER. Henley-on- Thames, Oxfordshire: Routledge & Kegan Paul (1983). Pp. xiv+437. Price s

Bertrand Russell once wrote that 'all the animals that have been carefully obse rved . . , have all displayed the national characteristics of the observer. Animals studied by Americans rush about frantically, with an incredible display of hustle and pep, and at last achieve the desired result by chance. Animals observed by Germans sit still and think, and at last evolve the situation out of their inner con- sciousness'. Walker is English, so he hedges his bets. He thinks that rats are probably brighter than Hull did, and that chimpanzees may be less insightful than their most ardent promotors would have us believe.

The first three chapters give a history of the study of thought in animals; first by philosophers, then by Darwin and his immediate followers, and finally by academic psychologists. The next three chapters compare the brains of different animals, outline the functional organization of the brain, and consider the possible selection pressures for brain size and intelligence. The core of the book is in the next three chapters which analyse the literature on the perception, memory and communication of animals as

studied in the laboratory. The conclusion briefly considers consciousness, encephalization of function and continui- ties and discontinuities between animals and man.

This is a literate book which is written in an attractive style. There are many people outside psychology, parti- cularly philosophers, who are interested ha what animals can and cannot think, and this book will give them a reliable and interesting account. For zoologists and psychologists it provides a novel mix of zoology, psy- chology and comparative neurology. The book was well worth writing.

I am less sure that the book contributes to the academic debate within psychology on such issues as animal memory or the cognitive achievements of chimpanzees. The coverage of recent work on memory mechanisms is thin, although this is an area which is now attracting great interest amongst learning theorists and neuro- psychologists. The author 's treatment of experiments on chimpanzee cognition and language is cautious, but he has no new points to make. But I suspect that it was not for psychologists working in this field that the book was written.

R. PASSINGHAM

Department of Experimental Psychology, South Parks Road, Oxford OX1 3UD, U.K.

Biology of the Reptilia. Vol. 12. Physiology C. Edited by CARL GANS & F. HARVEY POUCH. London: Academic Press (1982). Pp. xv+536. Price s

Biology of the Reptilia. Vol. 13. Physiology D. Edited by CARL GAYS & F. HARVEY POUGH. London: Academic Press (1982). Pp. xiii+345. Price s

Reptiles are not the most popular animals as subjects for ethological studies, although they are increasingly be- coming the object of intensive investigation in Nor th America, where most of the authors who have contributed to these two volumes are based. Reptiles are ideal sub- jects for certain kinds of investigation, particularly those concerned with interactions between the environment, physiology and behaviour. This is because, as stressed by Gans & Pough in their Introduction to Volume 12, the dependence of physiology on environmental factors is more clear-cut in reptiles than it is in endothermic animals such as birds and mammals.

The focus of most of the chapters is physiological though, in many, there is a keen awareness, both of the way physiological state influences and constrains be- haviour and of the role of behaviour in changing physio- logical state. Huey's chapter on temperature, physiology ~/nd ecology draws attention to the revolutionary effect on studies of thermoregulation brought about by the recog- nition that reptiles largely control their temperature by behavioural means. The cost-benefit approach discussed in this chapter is highly relevant to comparable ap- proaches to motivation in other animals. Other chapters in Volume 12 look at specific aspects of reptile ther- moregulation: Avery discusses the investigation of body temperature and thermoregniatory behaviour in the fidd, Bartholomew discusses physiological control and Fur th & Turner consider sensory, neural and hormonal aspects. A point stressed repeatedly in these chapters is that reptiles are not just unsuccessfnl endotherms. Rather, they represent an alternative way of coping with a variable environment, one that is as effective and much less energetically expensive than endothermy.