ZYGQNEMACES, 91 
C. Chlorophyll bands single. 
Spirogyra condensata. Vauch. 
Sterile cells with the extremities truncate, and commonly 
1 to 34 longer than the diameter. Chlorophyll bands single, 
rarely two, making 14 to 2 turns of the spiral. 
Spores broadly obtuse, ovoid, or subspherical, membrane even, 
chestnut colour. 
Sporiferous cells turgid, and usually shorter than the spores. 
Size. Cells 04 mm. diam., zygospores ‘035-04 mm. diam. 
Cleve Monog. Zygn. p. 21, t. v.f. 1-7. 
Conjugata condensata, Vauch. Conf. t. 5, f.2. Gray Arr. 
i, 298. 
Zygnema varians, Hass. Alg. t. 29, f. 8 and 4. Jenner 
Fl. Tunb. Wells, 180. 
Zygnema Woodsii, Hass. Alg. t. 83, f. 2. Jenner Fl. Tunb. 
Wells, 180. 
Spirogyra torulosa, Kutz. Tab. v. t. 20, f. 2. 
Spirogyra nodosa, Kutz. Tab. v. t. 20, f. 3. 
Spirogyra arcta, Kutz. Tab, v. t. 21, f. 2. 
Spirogyra condensata, Kutz. Tab. v.t. 22, f. 3, Petit Spiro- 
gyra, p. 22, t. 9, fig. 6-8. 
Rhynchonema Woodsii, Kutz. Tab. v. t. 34, f. 2 (not of Nord. 
and Wittr. Exs., No. 789). 
Spirogyra Flechsigii, Rabh. Hedw. i. p. 46. 
Zygnema quininum, var. Hass. Ann. Nat. Hist. x. (1842) 35. 
Spirogyra ulotrichoides, Kutz. Tab. v.t.21,f. 3. 
Spirogyra varians, Kutz. Sp. Alg..p. 489. Petit Spirogyra 
p. 49, t. 4, f. 1-8. 
Spirogyra inflata, Kutz. Tab. v. t. 21, f. 1-8. 
In pools, Fruiting in spring. 
From the number of synonyms quoted above, it may be inferred that 
this isa variable species. All the forms seem to be included by Petit 
under his Spirogyra condensata and 8S. varians. 
Hassall thus alludes to a peculiar nodoluse growth of some of the 
forms :—‘‘ When a number of cells unite in regular order with those of a 
neighbouring filament, no inflation of any of these occurs; but it fre- 
quently happens that several adjoining cells of a filament for some reason 
or other do not unite, although the remaining ones in that filament do, 
in which case those which have not yoked themselves swell up, assuming 
a monoliform appearance, and at the same time frequently emit blind and 
irregular processes or prolongations, by which the cells manifest the 
strong tendency which they have to conjoin themselves, but which some 
cause, not evident, would appear to have frustrated. In some speci- 
mens the number of inflated cells and blind processes is but small, 
while in others the elongated cells are more numerous than those which 
have united in the ordinary manner.” A similar circumstance may 
sometimes be observed in S. longata, especially in the short-celled 
forms. 
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