560 Rev. A. Irving — Reply to Prof. Mull. 



tliat Prof. Hull seems to suppose that the task which I had set my- 

 self was more ambitious in its scope and aim than I was conscious 

 of; it was not my pui'pose "to review the whole question of the 

 relations of British Permian and Trias " in a paper which was 

 limited by its title to the European rocks, and from which these 

 systems in other parts of the world were intentionally omitted. 

 My idea was rather to give to readers of the Geol. Mag. an oppor- 

 tunity of forming some judgment on the results which might be 

 fairly gathered from a digest of the oj)inions collected from the 

 various members of the "Sub-Committee on Permian and Trias," 

 taken along with the information which exists in the literature of 

 this subject in England and on the Continent, more especially in 

 Germany ; and to raise discussion thereupon before the assembly 

 of the Berlin Congress in 1884. My starting-point in this investiga- 

 tion was the elaborate table of the Permian and Triassic rocks of 

 England and the Continent, which Professor Hull himself was good 

 enough to send in to the Committee, before the duty was entrusted 

 to me, in conjunction with Mr. De Eance, of doing the work of 

 ■' Eeporters ' of the Sub-Committee. I had read and seen enough of 

 Continental geology to perceive at once how inadequately Professor 

 Hull had represented that side of the question in his table ; and it 

 was with much surprise that I found so high an authority giving 

 a reference (and his only reference) for information on the 

 Muschelkalk Formation to a statement contained in about half 

 a dozen lines of De la Beche's Manual of Geology, more than 

 fifty years old. It was somewhat incomprehensible to me that he 

 should go back so far for information, and thereby ignore the labours 

 of a whole generation of such workers as the two Credners, Quens- 

 tedt, von Hauer, Gtimbel, Zittel, Geinitz, and a host of others, 

 ' men of renown ' wherever these formations are intelligently studied. 

 Here I maj^ be permitted to thank Prof. Hull for the great services 

 which his otherwise copious list of references has rendered to me; 

 I assure him that I have worked them out carefully and honestly, 

 and that had he been good enough to add to them a reference to the 

 " Survey Memoirs of South Lancashire Coalfield, etc.," these too 

 would have been carefully studied. As it is, I must confess that 

 I have overlooked them, though it still remains possible for me to 

 consult them. This point therefore I must beg to waive for the 

 present. 



Had I started in the investigation committed to any very definitely 

 expressed opinions, it might have been suspected by some, who 

 shirked the trouble of following me in wading through the mass of 

 literature which I have had to consult, that I was not quite proof 

 against the temptation to twist things to answer my own ends. But 

 apart from the folly of such a course, when the literature of the sub- 

 ject is open to the whole world of critics, it may suffice, in order to 

 allay even Prof. Hull's suspicions, to mention that at the outset I 

 was certainly far more inclined (in common with several geologists 

 of no mean standing) to think much less of the distinction between 

 Permian and Trias than the investigation of the subject has led me 



