A Study of Some Coprosma Species of the Wellington Area with Special Reference to Natural Hybridisation

Abstract

A HISTORICAL REVIEW OF THE STUDY OF HYBRIDISATION. The word hybrid has come to have a very wide meaning and its precise definition is difficult. Darlington (1937) defined a hybrid as a zygote produced by the union of dissimilar gametes, but as Heiser (1949 p.645) remarked, "this definition if literally accepted means that practically all plants and animals are hybrids". Darwin used the term hybrid for crosses between species and called the progeny of inter-varietal crosses mongrels. Throughout this study, a hybrid is considered to be an inter-specific cross unless otherwise stated.