Mr Milne on the Parallel Bonds of Lochaber. 339 



to subsist on distilled water ; they must therefore be sup- 

 ported by some organic remains. We have tried to feed 

 them with the stalk and sporules of the protococcus without 

 any conclusive result. Inclosed in a vessel surrounded with 

 a cold mixture, they are unable to support a temperature of 

 — 18 centigrade degrees. This degree of cold kills them in 

 a few seconds. 



These facts ought to be impressed on the memory of those 

 who have occasion to visit glaciers ; they shew that there is 

 a peculiar organisation to be studied in such places. A nu- 

 merous series of microscopic beings belonging to the vege- 

 table and animal kingdom live and prosper in the bosom of 

 the ice, at a height of 2500 metres above the level of the 

 sea. 



On the other hand, it is not less clearly proved, according 

 to the laws which regulate the movements of glaciers, that 

 the entire mass renews itself at the end of a certain num- 

 ber of years, and contains the mineral, vegetable and animal 

 remains which exist on their surface and in their interior ; 

 they all reach in succession the terminal talus, and are again 

 found in the waters which flow from the inferior vaults. 

 Hence the origin of their great impurity, and the grey, 

 milky colour, without transparency, which characterises 

 them. — Comptes Bendua de VAcademie des Sciences, t. xxiv. 

 p. 1093. 



On the Parallel Beads of Lochaber^ with Bemarks on the 

 Change of Belative Levels of Sea and Land in Scotland, 

 By David Milne, Esq., F.It.S.E., Member of the Wer- 

 nerian Natural History Society ; of the Geological Society 

 of London, &c. 



There are few questions in geology which have given rise to so 

 many theories, and so much speculation, as the origin of the parallel 

 roads in the valleys of Lochaber. 



In the year 1817, the late Dr MacCulloch gave an elaborate 

 description of them, in a paper read before the Geological Society of 

 London. In the year 1818, Sir Thomas Dick Lauder read before 

 the Iloyal Society of Edinburgh a paper, full of equally interesting 

 details. Both of these observers suggested, in explanation of the 



