After describing the general appearance of these terraces, the author referred to the discussions which had taken place as to their formation. More than fifty years ago it was conclusively proved by Dr Macculloch and Sir Thomas Dick Lauder, that these parallel roads are the margins of ancient lakes, and since then the question has been whether these were freshwater or sea lochs. Mr Darwin, Dr Eobert Chambers, Professor Nichol, and others, have contended that they were marine; while Agassiz, Dr Milne Home, Mr Jamieson, and others, have maintained that they were freshwater.