This ambitious book sets out to cover aspects of the physiology, breeding, feeding and management of the major farm species in hot climates and to recommend how livestock development plans for such regions may be devised and carried out with success. It is intended primarily as a test for American university students and for those working in livestock programmes abroad.The first four chapters following the introduction are devoted to describing the animal's environment and the effect of the latter on physiology and production. Forages and concentrate feeds are then given a chapter each, and the next three are concerned with breeds and breeding. After four chapters on various aspects of management, there follow sections contributed by Dr. R.C. Jones on sheep production in semi-arid areas, Dr. H.C. Pant and the Late Dr. A. Roy on the water buffalo, and Dr. E.J. Seigenthaler and J.R. Stouffer, respectively, on the handling of milk and meat in warm climates. The final chapter deals with planning for livestock improvement.The book will be particularly welcomed for its section on climate and climate physiology. The author deals with the responses of animals to thermal stress and with the suitability of various types to hot conditions. This is probably the most complete review of the subject to appear in book form, although based mainly on work with cattle in the USA; its other special value lies in the way field applications of scientific data are examined. The author then discusses the value of various physiological and anatomical measurements for predicting suitability to hot climates and shows convincingly why an animal's adaptability to a certain environment should best be judged by its productive performance therein.The section on breeding may be the most controversial in the book for two main reasons. First, it is possibly misleading to students to characterise breeds by statistics presented in such a definitive fashion. Second, the discussion about genetic differences between tropical and temperate-zone breeds of dairy cattle may seem somewhat biased: so much of it is devoted to emphasising differences, for instance in survival rate, which are surely primarily due to environment. The picture might have been better balanced had data from European stock kept in tropical, rather than temperate, zones been used in this context, and it seems likely that the estimates of genetic differences for traits such as calving percentage would then have been smaller (page 289). The balance is not redressed in Chapter 10, where the comparative performance of European stock under tropical conditions is discussed briefly, because due weight seems not to be given to their very poor general record for reproduction and survival or to the high variability of their milk yields. It might also have been helpful to explain more clearly here how the scale of input costs, such as that of technical skill, is generally quite different for enterprises based on exotic compared with tropical stock and that this must be taken into account in assessing their relative efficiencies. Nevertheless, few will argue with the author's recommendations on the choice of breeding programme, and his views on selection criteria, especially his concept of 'total dairy merit', deserve to be widely read and adopted.The complex requirements of successful livestock development plans are the subject of the final chapter. This is welcome, because the backward state of tropical animal industries must be partly blamed on the inability of animal scientists to formulate effective plans and convince politicians of their value. However, in the discussion of the aims of development, a stronger case might have been made for assistance to the small livestock farmer.In general, the great advantage of this book lies in the way the author draws on his wide scientific and practical experience to establish the principles on which tropical livestock industries should be based. His introduction into the English literature of an unprecedented amount of information about animal production in Latin America will also be welcomed. The book contains numerous interesting photographs and an excellent index. Two serious disadvantages concern the high proportion of errors and the choice of reference system. Some errors of fact are almost inevitable in a book of this scope; others, due to overgeneralisation, are perhaps permissible in a text of this kind. But the editors have allowed too many linguistic errors to remain, which frequently obscure meaning or are actually misleading. Although it was not written primarily for research workers, an opportunity has been missed of providing them, too, with a most valuable reference work. So many interesting pieces of information are quoted with no note as to their original source, and this is particularly disappointing where whole arguments are built on unreferenced material (e.g. page 373 et seq.) or where data are unique and unpublished as, for instance, those pertaining to the Colombian Costeno con Cuernos breed (pages 287-288). It will also cause some surprise that passages have been quoted almost verbatim from other sources without acknowledgement (e.g. page 118). It is to be hoped that future editions of this potentially excellent book will be properly edited and will contain a complete list of references.Lucia Vaccaro.