12 



(7) In spite of the great stratigraphical difficulties, rendered 

 still more severe by the fact that the higher zones of the 

 Birkhill Shales pass laterally, one by one, into greywacke 

 undistinguishable from the greywacke above, as the strata 

 are traced to the northward, we are given detailed measured 

 sections showing the exact position, content, and extent 

 of each division of the Moffat shales. 



The result of this work, however, was not merely to rectify 

 knowledge of the geology of the Southern Uplands. It rendered 

 practically certain a number of inferences of world-wide application, 

 which are not stated in the paper, those there set out being solely 

 concerned with the area studied and the Moffat shale. To the reader 

 is left the task and the pleasure of generalising from the results 

 presented, and of realising how the foundations on which were based 

 so many anomalies and contradictions to scientific principles, and 

 so many obstacles to scientific progress, had crumbled away. 



(1) It had become possible to zone the older Palaeozoic rocks 

 by the same methods as have been used in newer rocks. 



(2) Graptolites are at least as valuable for zone-indices as 

 ammonites and other forms. 



(3) If patient and detailed mapping be based on it, such zoning 

 may be used to unravel the most complicated structures. 



(4) The Southern Uplands are proved to be a region which has 

 suffered from complex earth-movements of the type found 

 in great mountain regions. 



(5) In such a region the old method of ' regional ' mapping, 

 that is, the large-scale mapping of the greater lithological 

 formations, is inapplicable, and must lead to wrong 

 conclusions unless checked and supported by detailed 

 work in which due weight is given to palaeontological 

 as well as to lithological evidence. 



(6) So far from the evolution of the graptolites having stood 

 still while thousands of feet of rock were deposited, the 

 species and assemblages are found to change rapidly in 

 each few successive feet of rock. Instead of controverting 

 current theories of life-progress they give to them a new 

 and firm support. 



(7) Ingenious subterfuges such as Barrande's theory of 

 ' colonies ' invented to explain anomalies in the geological 

 distribution of organisms akin to those of the Southern 

 Uplands, are untrustworthy and unnecessary. 



It should be distinctly understood that this work was not 

 carried out in the light of preconceived theory, nor was it possible 

 for Lapworth to refer for guidance to a simple time-scale established 

 elsewhere. It was the result of a belief in the efficacy of geological 

 mapping, carried out with a minuteness and delicacy which had 



