BOTRYDIACER. 111 
Orver II]. SIPHOPHYCE. 
Unicellular alge, 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 trans- 
formed into oosporangia, others into antheridia. Cell contents 
green, mucilaginous, granulose, filled with chlorophyllose vesicles 
and starch granules. 
Propagation by free cell formation, or zoogonidia, or 
oospores. 
Plants aquatic or terrestrial, some marine. 
Famity I. Borryprtacem.—Propagation by free cell for- 
mation and by zoospores. 
Famity II. Vaucueriacra.—Propagation by oospores 
and zoogonidia. ; 
Famttry I. BOTRYDIACE. 
Plants small, terrestrial, unicellular. 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 spores; spore contents, in 
germinating, becoming modified into a number of sexual zoo- 
spores conjugating and forming isospores. 
Genus 52, BOTRYDIUM. Wall. 
Vegetative plants unicellular, increasing by cell division and 
zoospore formation; asexual uniciliate zoospores ;. sexual bici- 
liate isospores, sometimes globular, and alike capable of 
germination, sometimes compressed and hexagonal, furnished 
with a few tuberculate thickenings. 
See for information Braun’s “ Rejuvenescence,” pp, 128, 198, 220, 
274; Parfitt in “ Grevillea,” Vol.i., p. 103; Archer in “ Grevillea,” Vol, 
i., p. 105 ; Rostafinski and Woronin, “‘ Ueber Botrydium granulatum,” 
1877; Lawson in “Trans. Bot. Soc., Edinburgh,” vi., 424; Archer in 
‘Quarterly Journal of Microscopical Science,” 1878, pp. 446-452, 
R 
