52 POPULAR ILLUSTRATIONS OF 



It is not known as yet if any other animal lived in those ancient 

 seas. On this subject the stone book is silent. There is, however, 

 no decided proof that other animals may not have existed coeval 

 with the Eozoon, although their remains are not found in the 

 Laurentian rocks. They may have been destroyed by the heat, which 

 metamorphosed the sediment of those seas into Labrador felspar, 

 hypersthene, crystalline limestone, and beautiful green veined 

 marble, but which left intact the cast of the Foraminifera, and so 

 perfectly that the fossilised pseudopodia may be seen like tufts of 

 silver wire radiating through its canals and chambers. 



For the time being, then, at least, the Eozoon Canadense must be 

 considered as the oldest example of organic structure which the 

 records of geology have revealed to us ; and we must receive as a 

 fact of science that the lowest known sedimentary strata, for the 

 depth of from four to sixteen miles round the earth, have been 

 formed by the lump of jelly called the Amoeba. The student will 

 note that although these Laurentian rocks have only been observed, 

 say, in North America, Ireland, Sweden, &c., yet the geological 

 inference is that they would be found to occupy the same position 

 in all other parts of the world if the more recent formations were 

 removed. Thus, were I to bore into the crust of the earth at 

 Colchester, I should expect, at a distance of 13 J miles, to come 

 down upon the Laurentian rocks. At the time of their deposition it 

 is probable there was no land anywhere on the face of the globe, 

 which was one vast sea until the disturbing forces of central heat 

 from time to time kindly upheaved masses of land, which in his own 

 time the Creator peopled with living things. 



There is something truly practical and satisfactory in the revela- 

 tions of a science which shows to us how gradually the crust of the 

 earth was built up, and how far down that vista of time, in which 

 the imagination may revel in awe and wonder, those mighty pre- 

 parations were begun which culminated in the creation of man 

 himself. 



In the second or Lower Paleozoic period, Foraminifera have been 

 detected by Ehrenberg in the green grains which occur in the sand- 

 stone near St. Petersburg ; and, what is remarkable, there are many 

 of them referable to genera if not species now existing in our seas. 

 But the Foraminifera are not now found alone, on the contrary, they 

 are associated with animals belonging to all the other sub-kingdoms. 



There are no less than nine classes of animals found in the strata 

 immediately above the Eozoic ; but then we cannot now, as we did 

 yesterday, reason upon these animals as existing in the first dawn 

 of life. The discovery of Eozoon Canadense makes the fauna of 

 the Silurian system, comparatively speaking, modern, although the 



