312 A Rare British Freshwater Alga, [Sess.^ 



Oscillatoria Agardhii, but is willing to accept M. Gomont's 

 designation.-'- 



Although The Haining Loch, so far as known, is the only 

 locality in Britain for Oscillatoria prolijica, it is present in 

 several other countries. It was found, for example, in the 

 United States, near Boston, in 1892, and described as 

 Oscillatoria diffusa. It has been noted from Lake Morat, 

 in Switzerland; and in Migula's book on Algee (1908) it 

 is reported on from " Lakes in Switzerland." Again, in 

 Dr E. Lemmermann's ' Algen ' (1907) it is remarked that 

 this plant was formerly common in the Eatzeburger Lake, 

 North Germany. 



A short description may now be given of the Oscillatorise 

 in general, and of this Haining Loch species in particular. 

 Of the six classes into which Algse are now divided, the 

 Oscillatoriacese are relegated to the lowest class — viz., the 

 Myxophycese (Cyanophycese), or Blue-green Alga3. It has 

 been said, indeed, that the Blue-green Algse " must be looked 

 upon as an archaic group, which is very little in advance 

 of the Bacteria." " The genus Oscillatoria," remarks Pro- 

 fessor West, " is found in great profusion in all kinds of 

 wet situations, and sometimes on damp ground, or in hot 

 springs. Mocculent masses of Oscillatoria are often found 

 floating on the surface of ponds and ditches after sunshine, 

 and they commonly give off a more or less distinctive odour." ^ 

 This odour has been attributed to " the decay of highly nitro- 

 genous organic matter, in which partially decomposed sulphur 

 and phosphorus compounds play a large part." The structure 

 of the Oscillatorise is of the simplest kind. They generally 

 consist of a single row of cells, termed anmdi in Greville's- 

 time, and are either with or without an investing sheath. 

 Dr Greville's original designation of Lynghya and M. Gomont s 

 name of Oscillatoria for The Haining Loch genus do not really 

 represent much difference, as they simply mark off the plants 



^ In an interview which Mr F. L. M'Keever had lately at Hamburg with Herr 

 Selk of the Botanische Staats Institut on the subject of freshwater Algse, that 

 ardent German Algologist said that he had found both these forms in the Elbe, 

 and that he considers 0. "prolijica and 0. Agardhii to be identical, the latter being 

 only somewhat larger and better grown than the former. 



^ * A Treatise on the British Freshwater Algee,' by Professor G. S. "West, 

 p. 336. 



