THE LOWER FORMS OF LIFE. 51 



Now, beginning with the first fossiliferous period, which I propose 

 to term " Eozoic," as used in the above table, we find that these Lau- 

 rentian rocks, composed of quartz, slate, and limestone, forming in 

 many parts a beautiful veined green marble, occupy in Canada 

 and New York an area of 200 square miles, and have a known 

 thickness of 30,000 feet, and an assumed one of 90,000 feet, or, as 

 Sir William Logan has suggested, a thickness which " may possibly 

 far surpass that of all the succeeding rocks from the base of the 

 Paleozoic series to the present time, carrying us back to a period so 

 remote that the appearance of the so-called primordial fauna may 

 be considered a comparatively modern event." 



This extraordinary formation has been recently proved to have 

 been formed almost entirely by Foraminifera. In other words, the 

 rocks are the remains of the shells of one of these animals, to which 

 the name of Eozoon Canadense has been given. This discovery, one 

 of the most interesting and important that geological science 

 has afforded us, was made by Sir William Logan, the Superintendent 

 of the Canadian Survey, and Dr. Dawson, the Principal of McGill 

 College, Montreal, guided by the information given them in Dr. 

 Carpenter's " Introduction to the Study of Foraminifera." The 

 details of the subject have been worked out with great care by Dr. 

 Carpenter himself, who published in the Intellectual Observer for 

 May, 1865, a most valuable and interesting paper, illustrated with 

 coloured and tinted plates, giving the history and showing the struc- 

 ture of this interesting fossil. To this memoir, and to one by Dr. 

 Eupert Jones, in the Popular Science Review for April, 1865, 

 and also to the papers of Dr. Dawson in the Journal of the 

 Geological Society, vol. Ixxxi., page 51, and of Sir W. Logan, in 

 page 48 of the same journal, I must refer those who wish to know 

 more than the limits of this work will permit me to say. 



The Amoeba which formed the shell of the Eozoon Canadense in 

 those ancient waters was at least twelve times the size of any known 

 living species of the present day. And if you will be good enough 

 to refer back to my illustration of Orbitolites in the last chapter, and 

 imagine it to be a foot in diameter, and thickened proportionately 

 by placing one disc above another, you will obtain for all practical 

 illustration an idea sufficiently comprehensive of the representative 

 of the oldest living thing in the history of the world. And should 

 you ever hereafter be sailing on Lake Huron, or wandering among 

 the Canadian scenery watered by the St. Lawrence, it will be as well 

 to bear in mind that for that portion of the earth's crust we are 

 indebted to the labours of myriads of amcebiform creatures who 

 have left their remains as a mark of the service which they have 

 done in carrying out the great scheme of nature. 



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