The use of Lagrangian observation systems such as acoustically-tracked floats in the ocean and satellite navigated surface drifters requires a detailed and comprehensive development of the Lagrangian formulation of fluid dynamics. Professor Bennett's book is therefore a timely attempt to develop an understanding of the Lagrangian formulation for graduate students and researchers alike. The general solvability of the equations of motion is addressed and a unified account of turbulent diffusion and dispersion is offered. Application areas such as plankton patchiness in the ocean are also explored..