Cytoplasmic localization in early development. The ultrastructure and role of the polar lobe in development of molluscs / M.R. Dohmen and N.H. Verdonk -- Cytoplasmic determinants of tissue differentiation in the ascidian egg / J.R. Whittaker -- The multiple roles which cell division can play in the localization of developmental potential / Gary Freeman -- The control of the polar deposition of a sulfated polysaccaride in fucus zygotes / Ralph S. Quatrano, Susan H. Brawley, and William E. Hogsett -- Analysis of morphogenetic determinant in an insect embryo (smittia spec., chironomidae, diptera) / Klaus Kalthoff -- Germ plasm and pole cells of drosophila / A.P. Mahowald [and others] -- Maternal effect mutants of development. Temperature sensitive maternal effect mutants of early development in caenorhabditis elegans / David Hirsh -- A specific case of genetic control of early development : the o maternal effect mutation of the Mexican axolotl / Ann Janice Brothers -- Maternal effect mutations that alter the spatial coordinates of the embryo of drosophila melanogaster / Christiane Nüsslein-Volhard -- Pattern formation in developing systems. An analysis of cell-surface patterning in tetrahymena / Joseph Frankel -- Intercellular interactions and pattern formation in filamentous cyanobacteria / C. Peter Wolk -- Development of hydra lacking interstitial and nerve cells ("epithelial hydra") / Richard D. Campbell -- Pattern formation, growth control and cell interactions in drosophila imaginal discs / Peter J. Bryant -- Pattern formation and compartments in the tarsus of drosophila / P.A. Lawrence and G. Morata.