Repository: UIHistories Project: Board of Trustees Minutes - 1882 [PAGE 153]

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B . p e l l u c i d a , Cohn, (Hedwigia 1865, p. 82, T. I, Fig. 2.,

Filaments .00020 in. thick, motile, evidently articulated, with rounded ends; joints scarcely as long as thick; pellucid, containing but few granules. In a salt-water aquarium.

B . m i r a b i l i s , Cohn, (I. o. p. 81, T. I, Fig.l.)

Filaments thick, variously crooked and curled, with rounded ends, evidently articulated; attaining .00064 in. thick; joints half as long as thick, filled with numerous rather large granules. Threads twisted and woven through each other, forming a snow-white, slimy web. With the preceding.

DOUBTFUL SPECIES. B . t i g r i n a , Babh. (Flora Europ. Alg. II, p. 95.) Synonym: Oscillaria tigrina, Homer (Die Algen.Deutchlands p. 58.) Filaments rather thick.oscillating, evidently jointed, with slight and obtuse curves, now and then suddenly reduced in size, with rounded ends; pellucid, .00014 to .00018 in. thick; forming a thin white layer. In swamps and on wood under water. B . m i n i m a , Warm. Very small, flexible and actively moving; the longest .0016 in. .00007 to .00008 thick; jointed? distinguished by the order of the delicate stripes. Each joint about half as long as wide. Without granules. In sea-water.

CLADOTHBIX, COHN.

(Streptothrix, Cohn, Beitr. z. Biol. Bd. I, Heft 3, p. 204.)

Filaments leptothrix-like, very slender, colorless, without joints, straight or slightly undulating, or irregularly spirally wound, with apparent branches. I am unable to find a satisfactory difference between the genera Cladothrix and Streptothrix. Both are very doubtful genera. Compare Cienkowski's "Zur Morphologie der Bacterien" (Memoires de 1' Acad. imp. d. Sciences de St. Petersbourg. VII Ser. Tome XXV, No. 2, p . 11.)

C. d i c h o t o m a , Cohn.

Filaments repeatedly dichotomously branched, straight or slightly bent, .000012 thick, forming little webs (Baschen) .02 in. and more in diameter. In foul water, sometimes floating on the surface, sometimes attached to algae.

The branching inthiscase, as with Cladothrix Forsteri, is only apparent. The filament split themselves into two halfs, which independently elongate and so grow side by side; in this way the separated pieces are crowded to one side and appear as branches.