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CHAPTER RIGHT
THE GENUS DEBARYA WITTROCK 1872
Wittrock established the genus Debarya better to classify the
Mougeotia glyptosperma, so lucidly described and figured by
Anton de Bary in 1858. Since then several other species have been
discovered w^ith similar characteristics. The filaments are simple,
made up of cells two to twenty diameters long with ribbonlike, or
platelike, chromatophores with several distinct pyrenoids arranged
either in a single row, or scattered. The nucleus is centrally
located in the cell and attached to the side of the chromatophore.
The Debaryas resemble the Mougeotias during the vegetative
phase.
They differ from the Mougeotias, however, during the repro-
ductive phase. At the beginning of conjugation, or during aplan-
ospore formation, the reproductive cells become filled with a cel-
lulose colloid deposited as successive layers inside the cell walls.
Moreover, there are no cytoplasmic residues left in the gametangia
outside the spore walls. Conjugation is scalariform, and the gametes
unite in the conjugating tubes (isogamous). Aplanospores,
parthenospores, and akinetes have been observed in 2 of the
species.
The zygospores are compressed-spheroid, ovoid, or quadran-
gular-ovoid. The spores of 4 of the species are distinctly tricari-
nate, with an equatorial and two lateral keels. The median walls
may be further ornamented with pits, radial ridges, and undu-
lations.
All the 6 species are exceedingly rare, but they have been col-
lected in Europe, Asia, North America, and New Zealand; they
are probably more widely distributed than is surmised at the
present time.
Several of the species that were formerly described as belong-
ing to this genus have now been placed in the genera : Mougeotia,
Mougeotiopsis, Zygnemopsis, and Hallasia.
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