1890-91.] The" Green Balls'' of LocJi Kildonan. 421 



Extracts were also read from letters whicli had passed be- 

 tween Mrs Sprague, the Eev. Dr Stewart, Ballachiilisli, Pro- 

 fessor Spence Moore, and others, regarding these balls ; and a 

 resimxi was given of a paper in the ' Proceedings of the Eoyal 

 Society of Edinburgh' for Session 1885-8G, by G. W. W. 

 Barclay, Esq., F.RS.E., in which the algoid nature of these 

 lake-balls was shown. Professor Moore identified those sent 

 to liim from Loch Kildonan as Cladophora -^gagropila, Kiitz., 

 figured and described by Cooke, Hassel, and Dillwyn in their 

 respective works on British fresh-water alga\ The balls were 

 described as " lying in a depth of two to three feet, and 

 covering areas of many square yards, showing conspicuously 

 by their dark colour against the light sandy bottom. They 

 lie alongside of one another in great numbers, and vary in 

 size from about a quarter of an inch to three or four inches 

 in diameter. In some cases a complete small ball is found 

 inside a large one," as in the specimens exhibited. It is 

 supposed that these balls are formed by the long filamentous 

 alga of which they are composed being rolled by wind-cur- 

 rents along the bottom of the shallow water in which they 

 are found. So far as yet known, they are not present in any 

 Scottish loch except that of Lower Kildonan; but, according 

 to Professor Fischer of Berne, they are met with in several 

 European lakes, chiefly in Sweden, Norway, Northern Ger- 

 many, Austria, and Upper Italy. Professor Fischer states 

 that he also possesses an English specimen, from Ellesmere, 

 in Shropshire.^ The interior of the balls, when examined 

 under the microscope, is sometimes found to be filled with 

 diatomacecB. Dr Stewart has sent three specimens to the 

 Inverness Museum, with instructions that they should be 

 labelled thus : " Cladophora ^gagropila, from Loch Kildonan, 

 South Uist, 1890. Presented by Nether-Lochaber." 



1 These " green balls" are also found in several of the other Shropshire meres. 

 The following passage refers to Colemere, in the same district as Ellesmere, -where 

 some specimens seem to be very large: "They saw that the bottom" — about 

 three feet in depth — " was covered with balls of various sizes, from that of a nut 

 to some eighteen inches in diameter. ... It is supposed that there are eddies 

 and currents at the bottom of the mere that roll up the sunken moss and leaves 

 into these balls, and sweep them all to the side of the mere." — ' Rambles and 

 Adventures of onr School Field-Club,' by G. Christopher Davies, p. SI (second 

 edition, 1881 : C. Kegau Paul & Co.)— Ed. 



