PROGRESS IN PROTOZOOLOGY

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vine et al. 1980), there is no unique set of supraphylum or subkingdom
characteristics that will allow clear-cut taxonomic or evolutionary
separation of the protozoa from various other protists.]
Details will appear elsewhere (Corliss, in press, loc. cit.), but my
five major groupings — containing some 34 phyla, all told — may be
listed as follows:
I. The Protozoan Group (with 10 taxa: the "conventional" PROTO-
ZOA but excluding the "phytoflagellates" and certain "slime-mold"
groups);
II. The Protozoalgal Group (with 11 taxa: mostly pigmented groups
conventionally considered phyla or divisions by phycologists but orders,
or lower by protozoologists);
III. The Algal Group (with six taxa: the "usual" algae, including
the controversial red and brown algae but excluding forms found above,
under II, that would be here in phycological-botanical schemes);
IV. The Protozofungal Group (with four taxa, generally claimed by
both protozoologists and mycologists);
V. The Fungal Group (with three taxa, called "lower fungi" by
mycologists and to which they wolud add Group IV).
The areas of greatest controversy — with respect to attempts to delimit
a single taxon called the "PROTOZOA" — are, of course, within
the groupings I've labeled as numbers II and IV. But even with grouping
I, the problem of the "multicellular" Myxozoa (formerly Myxospora)
arises. In grouping II, the dinoflagellates have long been mistreated.
And the separation of certain forms into separate phyla in groupings
II and III — forms which ought to be united under a single phylum
(e.g., the "phytomonads" of II and the "chlorophytes" of III) — is unconscionable.
The kingdom PROTISTA itself is difficult to define, at least in a way
satisfactory to all. But to attempt to segregate a number of its three
dozen phyla into a unique group of "PROTOZOA," (with a capital "P"),
is no longer justifiable on the basis of data that have for some time
been available to us and that I have attempted to summarize here.
The following remarks were presented by the second speaker, Prof.
POLJANSKY. With some editorial changes, they are included here
in their entirety.
How should we interpret the question "Do the Protozoa constitute
a 'natural' group?" As I understand it, in the conventional sense, i.e.,
according to Darwin, "a natural group" is an assemblage of organisms
related phylogenetically because of their common origin.
Were I asked this question at the end of the 19th or in the early
20th century, my answer would have been simple and unequivocal. At
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