viii, 349 p. : ill., diagrs. ; 26 cm.

Contents. -The cell and the organism; a study in experimental zoology, by C. F. A. Pantin. -Sperm energetics; an account of work in progress, by Lord Rothschild. -The mechanics of ciliary movement, by J. E. Harris. -Some questions for the cell, by J. M. Mitchison.

-Experimental zoology and problems of arthropod evolution, by S. M. Manton. -Proprioception in arthropods, by J. W. S. Pringle. -Power in flapping flight, by T. Weis-Fogh. -Zoology, locomotory adaptations and the problem of electric fish, by H. W. Lissmann.

-Progress and prospects in ethology, by W. H. Thorpe.

-The comparative physiology of renal function in invertebrates, by J. A. Ramsay. -The haemocytic reaction of insects to foreign bodies, by G. Salt. - Concerning vision, by R. J. Pumphrey. -How lugworms move, by G. P. Wells.

-The efficiency of embryonic development: or, the price of the epigenetic process, by S. Smith. -Cell architecture and information in cellular differentiation, by C. H. Waddington. -The epidermal cell, by V. B. Wigglesworth. -Green, red, and blue bloods, by H. M. Fox.

-The physiological basis of behaviour in the Protozon, by J. A. Kitching. -Fertilization and the control of cell division, by M. M. Swann. -Molecular biology and the future of zoology, by L. E. R. Picken.