3i6 A Rare British Freshwater Alga. [Sess. 



materially lessen the quantity of this offending plant in the 

 following summer. Wishing to prepare a few micro, slides 

 of Oscillatoria 'prolifica, I resolved there and then to procure 

 some material. Armed with a note of introduction, I called 

 on the Professor, who entered quite freely into the subject 

 of the Alga floating in the loch in front of us, and I was 

 invited to step into the boat and " help myself." The 

 Professor then informed me that during certain seasons 

 the water was comparatively free of scum, as it had been 

 for the two previous summers, but that at present it was 

 " worse than ever." Therefore, he added, he had been 

 making some experiments by way of finding out what 

 would most effectually reduce the weed, and he had deter- 

 mined to try sulphate of copper. The result of this 

 experiment will probably form the subject of a future 

 communication to the Society. 



As this paper purports to deal only with The Haining 

 Loch Alga, I have said nothing about the estate itself, with 

 its fine woodland scenery and interesting flora, nor about 

 the surrounding district, so intimately connected with 

 Border history and poetry. For some notice of these, I 

 would refer to a communication read by me to the Society 

 in 1883.1 In the preparation of the present paper, I 

 desire gratefully to acknowledge the help so kindly given 

 me by Mr F. L. M'Keever, F.RM.S., well known to our 

 members as an authority on the subject of Freshwater 

 Alg^, and whose acquaintance with the literature of the 

 subject, both Euglish and foreign, is intimate and extensive. 



[In illustration of the above paper, slides of Oscillatoria 

 jprolifica and others of the same genus were shown under 

 the microscope. A number of lantern views of The 

 Haining, and of Selkirk and the surrounding district, were 

 also exhibited at this meeting and at the meeting of April 

 26, 1911. Two of these, showing The Haining House 

 and Loch, are here reproduced (Plate XXVI.)] 



^ " The Haining, Selkirk ; with Notices of its Antiquities, Topography, and 

 Natural History " — * Transactions,' vol. i. pp. 82-87. 



