MUSEUM OF COMPAKATIVE ZOOLOGY. 



13 



nection. It will thus be seen that specials have been transformed by 

 Professor Lesley into generals, entirely out of their original use ; and 

 remarks about one thing are said to have been made about another. 



After copying several pages from Professor Whitnej's "Metallic 

 Wealth/' he writes : "It appears from the foregoing that Mr. Whitney 

 accepts both the eruptive and the sedimentary theories of the formation of 

 the primary iron ores, and applies the former to unknown, inVisible masses, 

 antecedent to and now deeply buried under all, even the oldest rocks 

 which appear upon the present sm^ffice ; masses of far gi-eater size and depth 

 than the greatest yet discovered, proportionate to the greater scale of all 

 volcanic action in that prc-azoic day, and offering their sides and tops to 

 such erosion and solution as would of course happen in such unsettled 

 times, and be sufficient for producing the vast sediments of iron which 

 have been taken for volcanic outbursts of the molten metal. But there 

 is a fatal difficulty in tiie way of this hypothesis. These ore-beds are 

 not breccias. Deposits of the kind imagined would he conglomeritic ; 

 blocks of pig-iron would be seen scattered through strata of granite.'* 

 Here, again, he has entirely misunderstood Professor Whitney's views, 

 which wore that the great masses of ore in tlie Lake Superior district were 

 eruptive where they now are, and were never sedimentary deposits, 

 while associated with and derived from tliem are the hrecciated and con^ 

 glojiicritlc ores, as well as other sedimentary beds. If it is necessary, the 

 "pig4ron " can doubtless be found at Ovifak, Disko, in the basalt {I c 

 pp. 333-335, 353-361,480-489). 



In 1861 the rocks of the Marquette iron district were referred to the 

 Huronian system by Dr. T. Sterry Hunt, on the authority of Mr. Alex- 

 ander Murray.* Dr. Hunt regarded the Huronian then as tlic equiva- 

 lent of the Cambrian of the European geologists. 



Dr. Danat states concerning the iron ore of Michigan and elsewhere : 

 "Their alternation with chloritic and other schists and gneissoid rocks 

 shows that they arc metamorphic as well as the schists.'* The same 

 statement is made in the edition of 1874 (p. 74), and doubt is expressed 

 as to whether they belong to the Laurentian or Huronian (i>p. 151, 152, 

 159, IGO). Since the above was written the third edition of the Manual 

 has been published, but this affirms as strongly as ever that the iron 

 ore is in stratiffed sedimentary beds, and that it is distinctly interstrati- 

 fied with the schists. 



* Am. Jour. Sci., 1861, (2,) XXXI. 392-414; Canadian Nat and Geol., 1861. 

 VL 81-105, Vn. 127. 



t Manual of Geology, 1862, pp. 83, 84. 



