NA TURE 



{Nov. 13, 1873 



mastered by a few months' residence in a neighbouring 

 country, whilst the other had done more to develop true 

 culture than almost all other writings since. It is not 

 proposed simply to substitute German or French for 

 Greek, the advantages to be derived from which are now 

 fully absorbed into the spirit of the nation, but, by the 

 change, to leave a sufficient time, in addition to the edu- 

 cation in modern languages, for the study of the Natural 

 Sciences during the school-boy period. That the dead 

 languages form an excellent mental training no one doubts, 

 but that Physics and Chemistry do the same is daily be- 

 coming more certain ; and the time is not far hence when 

 the facts and methods of Physiology and Comparative 

 Anatomy will be so well known and assorted, that they 

 may be placed in the same category. 



THE SOUTHERN UPLANDS OF SCOTLAND* 



THE range of hills, which in Scotland extends from 

 the German Ocean to the Irish Sea, having a N.E. 

 and S.W. direction, has been aptly designated the Southern 

 Uplands. This range is nearly parallel in its course to 

 that of the Highlands proper. It exhibits hills, some of 

 which attain to an elevation approaching nearly 3,000 

 feet ; but its physical features, although marked in many 

 localities with scenes of great beauty, are devoid of the 

 stern and rugged grandeur which characterises the more 

 northerly mountains of Scotland. The hills of this range 

 usually consist of rounded and grass-covered undula- 

 tions, or long tracts of plateaux. They have been specially 

 named the "pastoral district of Scotland," and their 

 scenes have furnished subjects for many a pastoral song, 

 and many a border ballad. 



The Southern Uplands of Scotland are cut deeply into 

 by some of the streams which flow into the Solway Firth, 

 the Esk, the Annan, the Nith, the Urr, and the Dee being 

 the most important of them. They are drained on the 

 southward side by the Cree and the Luce ; on the north- 

 ward side they are the sources of the Ayr ; and the 

 Tweed and its tributaries drain a large portion of their 

 north-east area. 



In the early period of Scotch geology, the days of 

 Playfair and Hutton, the Southern Uplands were regarded 

 as affording no traces of the evidence of life in the rocks 

 which compose them ; and these rocks were referred to 

 the "primary" group. It was not until the discovery 

 of fossils in a limestone which occurs at Wrea in Peebles- 

 shire, in their higher portion, by Sir James Hall, that the 

 rocks which formed these hills were assigned to the 

 " transition " age. The terms " primary " and " transition " 

 have now ceased to be applicable to the nomenclature of 

 geology ; and the discovery by Prof James Nicol in 1S40, 

 in the flaggy beds of Greiston in Peeblesshire, of grapto- 

 lites, indicated the Silurian age of the strata here. Since 

 the discovery of Nicol, several geologists have added 

 greatly to our knowledge of the rocks which compose the 

 Southern Uplands. Other bands of graptolites have been 

 found richer in fossil contents than those first discovered ; 

 and these, along with a few other forms of organic re- 

 mains, have still further confirmed the Silurian age of the 



• Memoirs of the Geological Survey of Scotland, Sheets i, 2, 3 and 15, &c. 

 Explanations of, 1871, 1872, 1873, 



great mass of strata which make up the hilly country in 

 the. South of Scotland. 



The result of the observations made on the rocks of 

 the Southern Uplands up to the period when they came 

 under the notice of the Geological Survey of Scotland led 

 to the conclusion that the lowest strata exhibited were 

 referable to the Llandeilo age. That these Llandeilo rocks 

 were succeeded by deposits containing fossils, as in the 

 case of the Wrea limestone, indicating the horizon of 

 the Bala or Caradoc rocks, was also known — and 

 certain rocks which occur near the north-western margin 

 of the area in the neighbourhood of Girvan in Ayrshire, 

 have been referred by Sir Roderick Murchison to a still 

 higher position in the Silurian series. 



The labours of the Geological Survey of Scotland have 

 not only confirmed these conclusions, but have added 

 greatly to our knowledge of the nature of the Silurian 

 rocks of the South of Scotland. They have also fur- 

 nished subdivisions of these rocks, and a more ample 

 account of their arrangement and fossil contents. 



Every geologist familiar with the lower portions of the 

 Silurian rocks of the Southern Uplands, the Llandeilo 

 strata, had experienced great difficulty in recognising 

 horizons, in this series, such as would enable him to 

 divide these rocks into distinct portions. It is true that 

 bands of anthracitic shale abounding in graptolites were, 

 as regards their petrological nature, very distinct from 

 the rocks in which they were intercalated. The great 

 mass, however, of the Llandeilo beds of the Southern 

 Uplands consist of rocks known in old petrological 

 nomenclature as " greywackes " — ^a name which is still 

 retained for want of a better — and as these rocks differed 

 only in coarseness, and sometimes in colour, this circum- 

 stance rendered the division of the South of Scotland 

 Silurian rocks into separate groups extremely difficult. 

 And when it is added to this that contortions have greatly 

 folded and denudations have largely planed off the edges 

 of these rocks, the difficulty of making out distinct 

 horizons among the Llandeilo strata of the South of Scot- 

 land becomes very apparent. It is only by a careful, 

 continuous, and long series of observations recorded in 

 maps large enough to show all the contortions, the ins 

 and outs of the strata, that these rocks could be brought 

 into subdivisions enabhng them to be recognised. Such 

 have been the work of the officers of the Geological Survey 

 of Scotland ; and now we have in the explanatory notes 

 to some of the sheets which have been published, the 

 results of their work recorded, and the subdivision of 

 these Llandeilo rocks indicated. 



The explanation to Sheet 15, published in 1871, which 

 includes, among other matters, a description of the Llan- 

 deilo rocks occurring in that portion of the Southern 

 Uplands occupied by the north-west part of Dumfries- 

 shire, the south-west portion of Lanarkshire, and the 

 south-east portion of Ayrshire, contains the results of the 

 labours of the Survey among these rocks. There do not 

 appear, in any portion of the South of Scotland Silurian 

 strata, any rocks which appertain to an age older than 

 the Llandeilo ; and these Llandeilo rocks are referable 

 only to the Upper Llandeilo series, the Lower Llandeilo 

 or Shelve rocks of Murchison, the Arenig rocks or 

 Skiddaw slates of Sedgwick, being unknown in the dis- 

 trict. This Upper Llandeilo series exhibits itself in the 



