Phenomena and mechanisms in the early embryo: From egg to embryo. By JONATHAN M. W. SLACK. Cambridge University Press, 1983. Pp. 235. Paperback £9.95, $24.95. And Time,Space, and Pattern in Embryonic Development,MBL Lectures in Biology,vol. 2. Edited By W. R. JEFFERY and R. A. RAFF. Alan R. Liss,Inc. Pp. 383. £44 |