FLORA. 203 



and feeble, as is the case with all beginnings. 'We cannot 

 tell what the temperature which first admitted of this may 

 have been, nor what were the first forms which presented 

 themselves. Coincidences which are but of rare occur- 

 rence would have been necessary to give us fossil remains 

 of that early period ; nor are all organisms capable of 

 leaving tangible remains. We may infer from what we 

 know of existing organisms, that most probably these- 

 primitive organisms were of a soft consistency, integuments 

 and skeletons being the result of later development of the 

 primary types. 



' The primitive strata, notwithstanding their thickness, 

 supply us with few means of studying by these fossils the 

 character of the few widely separated vegetables and 

 animals inhabiting the waters during their deposit, but 

 the absence of these is no proof that vital organisms were 

 then non-existent. There are many remarkable geological 

 facts which are of such a nature as to give rise to the 

 thought that life had its first home, if not at the Pole 

 itself, at least in the neighbourhood of it, and that once 

 developed, it remained for a long time more active and 

 more reproductive in the countries which border on the 

 Polar Circle and the higher latitudes. The most ancient 

 fossiliferous deposits, which are, at the same time, those 

 most rich in organic remains, are found comprised within 

 the Northern Zone. They abound, moreover, in the cold 

 portion of that zone, from the 50th to the 60th degree of 

 North latitude, and still further to the north. We meet, 

 it is true, with Silurian formations in the south of Spain, 

 and in America, at a latitude corresponding nearly to the 

 35th degree of North latitude ; but the most celebrated 

 localities are situated more to the north, in Bohemia, in 

 England, in Scandinavia, and in the United States. The 

 Laurentian system acquires its greatest development in 

 Canada ; and the palaeozoic rocks associated with crystal- 

 line masses cover a considerable portion of the Polar lands 

 which stretch away to the north of the American lakes. 

 It is evidently the same with the parts of the ocean which 



