Test Sociedad Española de Estadística e Investigación Operativa Volume 13, Number 2. December 2004 Limiting Behaviour for Superadditive Bisexual Galton-Watson Processes in Varying Environments Manuel Molina, Manuel Mota and Alfonso Ramos Department of Mathematics, University of Extremadura, Spain Sociedad de Estad´ ıstica e Investigaci´on Operativa Test (2004) Vol. 13, No. 2, pp. 481–499