Correspondence — A. B. Hunt. 189 



an almost trustworthy working hypothesis from which to deduce 

 the ' era of transformation.' 



No doubt the earlier geologists misinterpreted the stratigraphy 

 of South Devon, and therefore their theory broke down ; but it was 

 a very elaborately argued theory, and was by no means a hypothesis. 



The Archaean doctrine of the schists is also a true theory, based on 

 innumerable observations. 



Mr. Somervail's view (No. 3) inferred the contemporaneity of 

 the schists with the Scabbacombe - Stoke Fleming rocks; but the 

 age of the schists will follow the age determined for the said rocks. 

 There is nothing approaching a hypothesis in the argument. 



No. 4, for which I am responsible, is based on a study of sediments, 

 and is independent of both petrology and stratigraphy. It was at 

 first based on a comparison of two specimens of thin-bedded sand- 

 stones with a specimen of a quartz-schist west of the Start. I first 

 advanced it in a paper to the British Association in 1891 ; contending 

 that the sandstone being Devonian the schist was Devonian too. 

 This, however, committed me to it being also Lower Devonian. 



In its then early stage this view was no more than a working 

 hypothesis, advanced before the Survey attacked the schist district 

 on its own account. It was a friendly challenge to my friends to 

 upset me if they could. But, strange to say, they never succeeded 

 in doing so, neither stratigraphically nor petrologically. My view 

 has now attained the unexpected dignity of a theory, and has actually 

 survived fifteen years' hostile criticism, and the accumulation of an 

 immense mass of fresh information. Howevei', it was never a mere 

 hypothesis, as the facts, though few, were undoubted. 



Until the publication of the Memoir there was one very weak 

 spot in my armour. I had entirely failed to trace the albite granules 

 of the schists into the Devonian rocks. Now that the quartz-felspar 

 veins, abundant in both series, have been proved to be quartz-albite, 

 that missing link is unexpectedly connected. 



The view No. 5 was first advanced by Mr. Hudleston, F.R.S., iu 

 his address to the Devon Association, and has since been adopted by 

 Mr. Lowe, F.G.S., and is apparently accepted by your reviewer. It 

 is equally subversive of all the others, whether based on petrology, 

 stratigraphy, or sediments. My contention that Nature will never 

 exactly reproduce in the same spot Archaean conditions in Devonian 

 times, is almost equally cogent against her reproducing Cambrian or 

 Silurian conditions. As my argument is that the rocks in question 

 (the quartz-schists) are Lower Devonian, and is not that these rocks 

 are not Archsean, Cambrian, or Silurian, any of these latter alterna- 

 tives is equally fatal to theory No. 4. Were I to be ousted from 

 No. 4 I should return to my former allegiance to Professor Bonney. 

 However, during the past fifteen years I have not been favoured 

 with a scrap of evidence against my Devonian theory from the 

 sediment point of view, and, so far as I can ascertain, there is no 

 petrological or stratigraphical fact in hopeless conflict with it. 



There is one point I may perhaps mention. Although the Torcross 

 volcanic rooks are very inconsiderable, the Scabbacombe - Stoke 



