528 



THE AZOIC SYSTEM AND ITS SUBDIVISIONS. 



meaning, is a justifiable proceeding. And it will be noticed that any 

 objection to the word Azoic, based on the ground that the formation in 

 question had been found to contain orgi^nic remains, and therefore not 

 to be properly called Azoic, was not in order at the time Mr. Logan 

 introduced the term Laurentian, as it was not then prctondod that these 

 lower rocks were fossiliferous. 



We proceed now to a discussion of the desirability of adopting the 

 term Archscan, introduced by Dana; and, with this end in view, it will 

 he necessary to look a little moro minutely into the way in which it is 

 used by this geologist. It will not have escaped the notice of the reader, 

 however, that much in this discussion turns upon the question whether 

 the so-called Azoic, Archjjcan, or Laurentian rocks are, or are not, destitute 

 of traces of organic life. Hence, in order to clear the way for what is 

 to follow, it will be well to take up this question at once. 



To those familiar with the geological literature of the past twenty 

 years, it will be evident that the only essential point before us is this : 

 Is the Mzoon a *' thing of hfe"1 If it is not, then all the accessory 

 evidence that the Archaean rocks are fossiliferous falls away of itself, 

 as we shall endeavor to show, as being utterly intangible and unsatis- 

 factory . 



Without going into anything like a detailed account of tne various 

 publications issued by the Canada Survey, or under its inspiration, 

 having it for their object to prove that there is a fossiliferous group of 

 rocks below the lowest Lower Silurian (the Potsdam or Primordial), 

 and of the discussion in regard to this point which has been going on 

 during the past twenty years, we may content ourselves with giving a 

 brief resume of the facts connected with this rather remarkable chapter 

 in the history of our geological progress. 



Another name having been given by the Canada Survey to the rocks 

 previously knpwm as Azoic, it became desirable that the formation thus 

 newly designated should be shown to be a fossiliferous one. For this 

 purpose that problematical body now so well known under the name of 

 the Eozooji was brought forward, and at the present time there exists 

 quite a voluminous eozoonal literature.* 



The first announcement in connection with the subject of the Eozoon 

 was made by Mr. Logan, in his Eeport for the year 1858. In 1859 he 

 exhibited specimens at the meeting of the American Association for the 

 Advancement of Science, but went no farther at that time than to 



* For a chronological catalogue of this literature, see "An Old Chapter of the 

 Geological Kocor.i," etc., by W. King and T. H. Rowney, London, 1881, pp. ix~liv. 



