II
‘it ,
narrower and perfectly elliptical, with abrupt ends. How the spores
b eh y e when germinating I have not yet had any opportunity of o b L y -
f foregoing details that the spores are always
t S i r act of conjugation. The spore formation,
therefoie, may be regarded as neutral, or we may assume that as in
exceptional cases spores may be formed by the instrumentality of a
w Z d tb ii ease the exception has become the rule, and the spores-
u id e tb parthenospores. and not as agamospores."
selY ? ? oiroumstances of development, Wittrock considers himone
Proposmg the genus Qonatonema for the two forms, the
m ^ e Z d 1 “lb” ! ” " ''" " - ’ ^bove observations kere
described as Mesocarpus:
Gonatonema n o tab ile . (Hass.) WiUr.
Sterile cells 8 to 10 times as long as broad, sometimes longer,
ygospore, front view cylindrical, side view bent so as to be
convex on one side concave on the other, truncate at the ends,
same diameter as the vegetative cells.
S iz e . Cells -012--015 mm.
Wittrock MesocarpeiB, p. 16, fig, 14.
Mosocarpus notabiUs, Hass. Alg. 170, t. 46 f 2
Mougeotia notabilis, Hass. Ann. Nat. Hist. x. p ‘ 46
Staurospermum notabile, Rabh. Alg. Eur. iii. 261.
Found in great abundance in
Hassall.
some brick fields near No ttin g
Hill.—Here follows the original description by H a s s a l l “ Filaments at first
bffinsr rftni’t * becoming augulated, the angle of flexion
bemg situate in the centre of each cell. Cells usually about 8 or 10
t r Z l T s i Z b f r e q u e n t l y longer. Sporangia non-symme-
We b being placed in the angle formed iueach of the cells."
We have nothing to add to this description, never having seen the
plant in question, and are able only to reproduce Hassall’s fi|nres.
Plate X L I r . fig. 3. a, sterile cells; h, fertile cells, after Hassall.
BOTRYDIAOE2E. I l l
Unioellular algse, usually at the time of fruiting bicellular.
Cells utricle-shaped, often prominently branched ; branches with
terminal vegetation, at length shut off by a septum, some tran s formed
into oosporangia, others into antheridia. Cell contents
green, mucilaginous, granulose, filled with clilorophyllose vesicles
and starch granules.
Propagation by free cell formation, or zoogonidia, or
oospores.
Plants aquatic or terrestrial, some marine.
F amily I. B otrydiaoeie.—Propagation by free cell formation
and by zoospores.
F amily I I . VAuoHERiAcEiE.— Propagation by oospores
and zoogonidia.
F a m i l y I. BOTEYDIAOF^.
Plants small, terrestrial, unioellular. Cell in the beginning
globose, afterwards clavate or pyriform, and inflated; vertex
rounded, a long time closed, attenuated downwards; base
divided into delicate hyaline radicles, filled within with a
mucilaginous green granulose cytioplasm, with age collapsing
at the apex, and finally wasting away. Cell contents modified
into an indefinite number of resting sp ores; spore contents, in
germinating, becoming modified into a number of sexual zoospores
conjugating and forming isospores.
Genus 52, BOTRYDZUM. Wallr.
Vegetative plants unioellular, increasing by cell division and
zoospore formation ; asexual iiniciliate zoospores ; sexual biciliate
isospores, sometimes globular, and alike capable of
germination, sometimes compressed and hexagonal, furnished
with a few tuberciilate thickenings.
See for information Braun’s “ Eejnvenesoenoe,” pp. 128, 193, 220,
274 ; Parfitt in “ Grevillea,” Vol. i., p. 103 ; Archer in “ Grevillea,” Vol,
i., p. 105 ; Eostafinski and Woroniu, “ Ueber Botrydinm granulatum,”
1877; Lawson in “ Trans. Bot. Soo., Edinburgh,’’ vi., 424; Archer in
“ Quarterly Journal of Microscopical Science,” 1878, pp. 446-452.
B
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