Symposium on Animal Speciation

Abstract

A SYMPOSTOM on "Ecological and Genetic Factors of Specia on in Aaimals" was held by the Istituto Italiano di Idrobiologia, Pallanza (Novara), Italy, during July 29-August 2. The meeting was sponsored by the Consiglio Nazionale delle Ricerche (Italian National Research Council), whose general secretary, Dr. A. Morelli, opened the symposium, which was attended by thirty-four biologists. Papers were read by : E. Baldi, Pallanza (isolation mechanisms in populations of plankton freshwater crustaceans); M. Benazzi, Pisa (genetic-systematic studies on Triclades); F. G. Brieger, Piracicaba (heterosis in population-genetics and evolution) ; H. Burla, Zurich (ecology of Drosophila species of Switzerland) ; U. D‘Ancona, Padua (Nemi‘s Daphniae during twenty-five years of observations) ; A. Dreyfus, São Paulo (sex-ratio in hybrids and its interpretation by the study of salivary chromosomes) ; M. Galgano, Florence (ecological and genetic factors in the sexual cycle of amphibians) ; J. B. S. Haldane, London (importance of disease in evolution and speciation) ; J. Heuts, Louvain (ecological and genetic factors in the speciation of the fish Gasterosteus aculeatus) ; F. Mainx, Vienna (chromosomal races of the Agromyzine Lirryomiza) ; B. Rensch, Miinster (histological transformations by change in body size) ; H. Spurway-Haldane, London (comments on Vavilov‘s law of homologous variation) ; V. Tonolli, Pallanza (isolation and stability of high-mountain Diaptomid populations) ; L. Trevisan, Pisa (evolution of the elephants during the Quaternary). Prof. Th. Dobzhansky, of Columbia University, New York, introduced the theme for discussion, and at the end of the meeting summed up the proceedings. The papers will be published in a special volume, edited by the Consiglio Nazionale delle Ricerche.