BOOK REVIEWS

land disappeared under water, including viewing it as an indifferently designed work On the beach the legendary Rungholt, east of the of other purpose. The author's skills lie in present island of Pellworm. A second Donald J.P. Swift the collecting and ordering of information. Mandrdnke occurred on 11 October, Chapters that attempt to take an overview, 1694. But the main and partially enduring such as those on natural preconditions and The Morphodynamlcs of the Wadden land losses, resulting in the formation of barrier-island development, are not Sea. By Jurgen Ehlers. A.A. Balkema: Jade Bay, the Dollart and the Zuider Zee, altogether successful, although they are 1988. Pp.397. DM 185, £52. 75. did not occur as the result of single events, always interesting. On the other hand, the but gradually, through many smaller relentless procession of maps, aerial THE Wadden Sea is the intertidal zone of stages. These land losses were due to a photographs and, above all, photograph the German Bight of the North Sea. lack of technical infrastructure capable of after photograph at ground level, has a Varying in width from 10 to 50 km, it is an protecting the vast forelands from the hypnotic effect. Somewhere through the expanse of tidal channels, flats, inlets, destructive effects of later surges in later 393 figures, these vistas of misty dunes, flood and ebb deltas, barrier islands and decades. Land reclamation occurred, but beaches and marshes, and of tidal flats estuaries that extends from Den Helder only through projects that lasted for extending to the horizon, seep into the in the Netherlands to Blavandshuk in centuries. unconscious-youhave been there. D Denmark. It is important to appreciate this mono­ Donald J.P. Swift is a Professor in the Depart• Jiirgen Ehlers explains that while graph for the fine work of descriptive ment of Oceanography, Old Dominion Univer• mapping the geomorphology of the morphodynamics that it is, and to avoid sity, Norfolk, Virginia 235~9. USA. Wangerooge (map) sheet, "I came to realize the importance of both the major and minor bedforms of the Wadden physical topics: dimensions and scaling Sea .... At the same time, my observations Nature explained principles first, then fluid mechanics, led me to suspect that the remodeling of R. McNeill Alexander properties of materials, structures and the landscape [was occurring] at a much mechanisms. All the mechanics is intro­ faster rate than I had previously assumed". duced simply, including tricky topics such With his consciousness thus raised, Ehlers Life's Devices: The Physical World of as the bending of beams. There are no initiated an aerial photographic survey of Animals and Plants. By Steven Vogel. logarithms or trigonometrical functions, the Wichter Ee, a tidal inlet between the Princeton University Press:1988. Pp.367. and there is even an appendix as a barrier islands ofNorderney and Baltrum, Hbk $49.50; pbk $17.95. reminder of how equations work. No over a 30-day period. The resulting background in science is necessary to analysis of shoal and megaripple migra­ WHY do starfish have five arms? Why enjoy the book, only intelligence and the tion forms the core of this book, but there don't animals run on wheels? And isn't it willingness to stop and think. is much more. intriguing that spider silk has five times Here are a great many fascinating scien­ After chapters on barrier-island devel­ the strength of mild steel, and that prairie tific stories, including quite a lot that I did opment, recent geomorphological pro­ dogs (rodents, not canines) dig self-venti­ not previously know. Too often, though, cesses, morphodynamic units and histori­ lating burrows? Here is a brilliant and the explanations are frustratingly short. I cal development, the author rolls up his eccentric book that looks at living things doubt whether naive readers will get a sleeves and launches into a description, from an engineering point of view, assum­ clear understanding of the plastron of one by one, of the 35 barrier islands of the ing astonishingly little previous knowl­ aquatic insects, which enables them to Wadden Sea and their associated inter­ edge of science on the reader's part. breathe under water, from this brief, un­ tidal terrains. This roll call of islands, A summary of one chapter will give the illustrated account. I doubt whether they from Fan0, Mand0, R0m0 and Sylt in flavour of the whole. Under the same will appreciate the strange properties of the North Frisian Islands, through Wan­ weight of laundry, a sagging clothes line is slug slime, which enables slugs to crawl gerooge, Spiekerooge, Langeooge and less likely to break than a tight one. This while keeping the whole area of the foot Baltrum in the East Frisian chain, to helps us to understand why there is more perpetually on the ground; as the slug Terschelling, Griend, Vlieland and Texel tension in the wall of a large pipe than of a crawls the slime under each part of its foot in the West Frisian Islands, will for many smaller one, when both contain fluid at behaves alternately like a rubbery solid readers constitute the real strength of the same pressure: automobile tyres need (giving the slug a purchase on the ground) the book. thicker walls than bicycle tyres (although and like a viscous liquid (letting it slide The careful review of historical records the latter are inflated to higher pressure), forward). The sparkle of the book depends is another valuable contribution. Eight and arteries need thicker walls than blood on its pace, but there were times when it centuries of documents allow us to shift capillaries. Toy balloons do not inflate would better have been slowed down. from the time scale of fluid dynamical uniformly but start with a localized bulge, Professor Vogel is a distinguished bio­ processes at seconds, minutes, days and and blood vessels would be apt to swell logist who has discovered many revealing years into the lower portion of the geo­ similarly were it not for the peculiar prop­ things about the flow of water and air over logical frequency band. Within these eight erties of their walls. Our lungs need an animals and plants. He is also the author centuries we can resolve some of the internal coating of a wetting agent to make of a more advanced biomechanics book, event-dominated fine structure of the their 30 million tiny pockets (alveoli) swell Life in Moving Fluids, published by most recent phase of the Holocene trans­ uniformly when we breathe in; which Willard Grant, Boston, in 1981. In an aside gression of the North Sea basin. Impor­ leads to an explanation of why bubbles half way through his new book he tells us tant loss of land occurred in the storm form against the wall of a beer glass, not in the secret of his success, which is also the surgesoftheyears 1010,1020,1041,1075, mid-beer. book's philosophy: "A good way to make 1094, 1102, 1114, 1164 and 1282. The Professor Vogel suggests two uses for a neat discovery is to begin, not with your greatest single land loss resulted from the his book: as the basis of a course for non­ favorite organism, but with some physical surge of 16 January, 1362, the second scientists in liberal studies programmes property or phenomenon and then ask Marcellus flood, also known as the Grosse or, for biologists, as a preparation for how animals might take advantage of it". Mandrdnke (great mandrowning). Jade deeper biomechanical studies and more R. McNeill Alexander is a Professor in the Bay, the Dollart and Harle Bay were en­ advanced reading. Life's Devices will be Department of Pure and Applied Biology, Uni• larged, and in Nordfriesland vast areas of excellent in either role. It is organized by versity of Leeds, Leeds LS2 9JT, UK. 308 NATURE · VOL 338 · 23 MARCH 1989