1863.] 267 [Lesley. 



For Mr. Lesley's ability as a stratigi'aphical geologist, I have the- 

 highest respect; and with reference to the present subject, would 

 merely desire to point out that he may not have possessed a sufficient 

 number of facts to warrant some of his generalizations, on which in 

 the meantime I would, for the reasons above stated, desire geologists 

 to suspend their judgment. 



J. .W Dawson. 



McGiLL College, Montreal, 



February 18th, 1863\ 



Mr. Lesley remarked that he read this communication of 

 his friend, Professor Dawson, with great pleasure, as it would 

 prevent any mistake about the nature and importance of the 

 discussion, and any undue weight being attadied to his own 

 suggestions ; that no one was more convinced than himself 

 that there could be no excuse for dogmatism where so little 

 was known, and therefore, that he had intended rather to 

 suggest than to defend those opinions expressed in his paper^ 

 which had drawn down so earnest and valuable a caveat from, 

 so high a source. To defend them would require long and 

 systematic researches on the ground, if even then, the too- 

 easily accepted present standpoint of pal'cTsontology would not 

 hide the truth from view behind immovable obstacles. So- 

 long as apparent specific identity in organic forms continues 

 to be accepted as the supreme test of stratigraphical horizon, 

 discord is iijevitable. When palaeontology is prepared to re- 

 turn under the mild dominion of her mother, lithology, which 

 she has at least one-half repudiated, geology will advance 

 more rapidly in her work. 



Professor Dawson's firs-t objection is a begging of the very ques- 

 tion, Whether the coal-measures of Nova Scotia are " enoruiously 

 developed." That, in one little spot of the earth's surface like Nova 

 Scotia, and that too midway between the great coal areas of America 

 and those of Europe, wherein the thickness of coal-measures proper 

 range from 2000 to 5000 feet, if they even attain the latter size^ 

 there should be an anomalous deposit of 25,000 feet, is incredible. 

 What the great Bohemian palaeontologist, by unerring instinct, said 

 to us after our thirty years' war over the Taconic system, there must 

 be a mistaJce somewhere, I must repeat to those who so " enor- 

 mously develop " the Nova Scotia coal-measures. And my inten- 



