ABSTRACT
There has been a long history of the use of life-cycle characters in attempts to elucidate the phylogeny both of the cestodes and related groups of platyhelminth parasites. Perhaps the most notable historical example is the so-called 'cercomer theory' of Janicki (1920), used primarily for evidence of a link between the cestodes and the trematodes. The first comprehensive modern attempt to compare cestode life-cycles was undertaken by Joyeux and Baer (1961). Detailed studies during the 1950s and 1960s of cestode eggs and larval cestode morphogenesis resulted in significant reviews by Rybicka (1966) on the structure of cestode eggs and Voge (1967) and Šlais (1973) on cestode larvae. Subsequently, two major but not entirely concordant attempts to utilize these data in analyses of the phylogeny of the cestodes were made by Freeman (1973) and Jarecka (1975). A summary was provided by Ubelaker (1983a,b) in reviews of egg and metacestode development, and was subsequently updated by Burt (1987).
