30 Reviews — Whitney and Wadswortlis Azoic System. 



Huronian systems of the Canadian geologists, and admitted that 

 Eozoon was organic. I^his critical narrowness is, in the same page, 

 accompanied by a bold inaccuracy, by which a hesitating opinion of 

 Murchison is converted into a contradiction. 



If so conservative a geologist, as Murchison was in his later years, 

 comes under the censure of Prof. Whitney and Dr. Wadsworth, we 

 are not astonished to read in these pages that " no reliance is to be 

 placed in Logan's much vaunted work and sections, beyond the ques- 

 tion of surface distribution," and that Dana, James Hall, and, 

 indeed, the great bulk of American and Canadian geologists, became 

 involved in confusion and error when they got among the crystalline 

 rocks. 



Our authors bring into prominence a very serious discrepancy 

 amongst the American students of the old rocks. Dr. Sterry Hunt 

 definitely places the Norian below the Huronian, and the Huronian 

 below the Montalban. But Prof. C. H. Hitchcock, as quoted by our 

 authors, makes both the Norian (pp. 390, 392) and the Huronian 

 (pp. 393, 461) to be younger than the Montalban. In the British 

 area. Dr. Hunt has identified the Huronian and the Montalban ; but 

 his older series is less crystalline than the younger, and the present 

 writer hopes soon to publish stratigraphical evidence which will tend 

 to reverse the order which Dr. Hunt has announced, so far as these 

 islands are concerned. This is a matter which requires some 

 explanation from American geologists. 



Our authors, " in view of the contradictions and confusion of ideas 

 thus shown to exist among the most eminent geologists in reference 

 to the nomenclature of the oldest crystalline rocks," offer "a con- 

 tribution " towards a " more definite understanding " of the subject. 

 The first pai-t of this " contribution " is a defence of the term 

 " Azoic." It is, perhaps, not unnatural that Messrs. Whitney and 

 Wadsworth should uphold the use of a term which was originally 

 proposed by Messrs. Foster and Whitney, Our authors maintain 

 that the usual evidence for the existence of organic remains in the 

 rocks below the Cambrian is insufiicient. Eozoon, they contend, is 

 a mineral structure, and limestones may be formed without the 

 agency of animals or plants. Apatite, also, and the forms of carbon, 

 graphite and the diamond, occur as the original constituents of rocks. 

 All this may be consistently admitted without accepting the term 

 " Azoic," which implies, not that no traces of life have been found, 

 but that none occur, in the old rocks. This ai'gument appears to 

 have afi"ected Dr. Sterry Hunt in a very singular manner. In his 

 work on South-eastern Pennsylvania, in 1878, he uses the term 

 " Azoic " ; but, since the publication of the book before us, he has 

 announced ^ the adoption of the word " Hypozoic." This is like 

 converting a sinner to the error of his way. 



A second " contribution " towards a settlement is the statement 



that " no fact is better or more generally recognized than this : that 



geological time can only be kept by the aid of palseontology " (p. 652), 



an assertion which will come to most British geologists as a revelation. 



1 Geol. Mag. Nov. 1884, p. 506, 



