102 RELICS OF TRIMEVAL LIFE 



in the Laurentian graphite ; secondly, that the 

 general arrangement and microscopic structure of 

 the substance corresponds with that of the carbon- 

 aceous and bituminous matters in marine formations 

 of more modern date ; thirdly, that if the Laurentian 

 graphite has been derived from vegetable matter, 

 it has only undergone a metamorphosis similar in 

 kind to that which organic matter in metamorphosed 

 sediment of later age has experienced ; fourthl}-, 

 that the association of the graphitic matter with 

 organic limestone, beds of iron ore, and metallic 

 sulphides, greatly strengthens the probability of its 

 vegetable origin ; fifthl\-, that when we consider 

 the immense thickness and extent of the Eozoonal 

 and graphitic limestones and iron ore deposits of 

 the Laurentian, if we admit the organic origin of 

 the limestone and graphite, we must be prepared 

 to believe that the life of that early period, though 

 it may have existed under low forms, was most 

 copiously developed, and that it equalled, perhaj^s 

 surpassed, in its results, in the way of geological 

 accumulation, that of any subsequent period." 



Let us take, in connection with all this, the fact 

 that we are dealing with the deposits of the earliest 

 o.ean known to us — an ocean warm and abounding 



