THE EOZOIC AGES. 35 



subsequent progress of the creative work. As to the 

 mystery of the origin of living beings from dead 

 matter, or any changes which they may have under- 

 gone after their creation, it is absolutely silent. 



NOTE. To the statement respecting metamorphism on p. 

 21, it should be added that the gneiss of the Laurentian must 

 have been originally different from ordinary sediments, and 

 probably consists largely of the material of the primitive 

 crust, arranged in beds under the agency of heated water, 

 and not subjected to any atmospheric decay. This subject is 

 discussed in my address to the British Association, 1886. 



