Abstract
Summary: The technique of somatic cell hybridization or the fusion of protoplasts of different plant species has reached the stage that it may be exploited by systematists for experimentally interpreting phylogenetic relationships of highly divergent lineages. The value of this technique is discussed in relation to others currently employed, and in relation to what we might expect to find at the levels of proteins, secondary products, and morphology based upon our knowledge of plant hybrids and animal hybrid cell cultures.