Dynamic Models in Biology BY STEPHEN P. ELLNER AND JOHN GUCKENHEIMER xxii + 329 pp., 25 × 18 × 2cm, ISBN 0 691 12589 9/ISBN 13 978 0 691 12589 3 paperback, US $45.00/GB£ 29.95, Princeton NJ, USA/Oxford, UK: Princeton University Press, 2006