|THE PARALLEL OF ONTOGENY AND PHYLOGENY 211
the foundation for so many modern studies, I shall present an explicit critique later (see pp. 221–228).
As a further elaboration, several authors tried to extend the concept of recapitulation itself. They reasoned that phylogeny is not the disconnected array of adult stages that Haeckel had envisaged, but a sequence of ontogenies (Garstang, 1922; Severtzov, 1927; Schindewolf, 1946). Recapitulation is the repetition of phylogeny during ontogeny. If phylogeny is construed as a sequence of complete ontogenies, then any stage held in common by ancestors and descendants is a "recapitulation." This theme was stressed by the Russian School of A. N. Severtzov and his followers (Severtzov, 1927, Matveiev, 1932; Yezhikov, 1933, 1937; Lebedkin, 1937; Kryzanowsky, 1939). This remarkable redefinition turned many accepted terms into their opposites. Thus, Schindewolf (1946) actually classified cenogenesis as a subcategory of palingenesis! For, in this new definition, palingenesis applies to any feature present in both ancestor and descendant, including common adaptations of juvenile stages.
We encounter the ultimate confusion in Peter's revision of the terms "palingenesis" and "cenogenesis." To him, any character held in common by ancestor and descendant is palingenetic (since it produces "recapitulation" under this widened and distorted definition). Any character newly evolved by a descendant is cenogenetic: "A cenogenetic feature reaches no further back in phylogeny than the species or group for which it is characteristic; a palingenetic [feature] is already present in evolutionary history" (1955, p. 68). Peter's concepts are totally divorced from the meanings they carried through 80 years of debate, since there is no longer any reference to the ontogenetic stage at which characters appear. The only distinction is between new ("cenogenetic") and old ("palingenetic"). This revision carries the further disadvantage (as Peter readily admits) that the terms are now purely relative in application. The malleus and incus of our middle ear are palingenetic with respect to our position among mammals, and cenogenetic when we are contrasted with reptiles.
Guidelines for a Resolution
Any reader who has worked his way through the labyrinth of the last few pages should now understand why ontogeny and phylogeny has become such an unpopular subject of late. When the well of new concepts has dried up, one can always argue about terms, permute their meanings, and arrange them in ever more complex classifications. I think that the time has come to make some distinctions and