Spirogyra fluviatilis Hilse

NEW YORK

DANGEARD, PIERRE. / Sur 1* existence de

?GARDE '

deux variétés du Spirogyra fluviatilis Hilse et
su.r le cytoplasme de ces algues. / Botaniste /

22(1/6): 15-32. 2 pl. 1931.---

In the i*ake of Annecy, Soirogyra fluviátil is occurs in two f^cfms that

do not appear to intergrade* One, var. ma,3or* (pp. 16, 1?) is dark green

and occurs mostly at depths of 1-1.5 si, ¿ its filaments are often 10-15 cm.

long and 46-5^1 wide and its cells 3-7 times as long as wide. The type, or

var* minor* (pp. 16, 17). is yellowish green, is found near the surface,

often drying out at low water on the margins of the lake; its filaments are

about 5 or 6 cm. long and 31-32^ wide and its cells 8-12 times as long as

wide. Both are commonly attached by basal rhizoidés, rare in the genus,

¡ f|p§|¡ I

and both have three chromatophores to a cell. Both have "propagules”,
cells with crowded chromatophores and large accumulations of starch.
Zygospores have not been observed in the specimens from this lake* The
protoplasm of both contains cytosomes (ehondriosomes) in the form of small
rods about 2ji long and granula about half a micromillimeter in diameter,
which, behave like distinct elements. There are also minute "paillettes*,
showing active brownian movements. These are observed chiefly in the
peripheral parts of the vacuoles in contact with the protoplasm,
occasionally moving into the interior region of the central vacuole* Their
chemical nature is unknown* — Marshall A. Howe.

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