From the Editors. 369

Bringhurst, R.S. and V. Voth. Breeding octoploid strawberries. 371

Dewey, D.R. Wide-hybridization and induced-polyploid breeding strategies for perennial grasses of the Triticeae tribe. 383

Einspah, D.W. Production and utilization of triploid hybrid aspen. 401

Hermsen, J.G. Th. Nature, evolution, and breeding of polyploids. 411

Hermsen, J.G. Th. Mechanisms and genetic implications of 2n-gamete formation. 421

Hermsen, J.G. Th. The potential of meiotic polyploidization in breeding allogamous crops. 435

Hermsen, J.G. Th. Haploids as a tool in breeding polyploids. 449

Hermsen, J.F.Th. Some fundamental considerations on interspecific hybridization. 461

Rook Review. 475