THE EARTH THE ABODE OF LIFE 



authority leans to the idea that the conditions when life 

 would have been possible on the earth were finished long 

 before the earth had finished growing, and that these con- 

 ditions may have existed when the earth was about the 

 size of Mars. Consequently the first beginnings of life 

 may have existed at depths hundreds of miles below the 

 earth's surface of to-day. The life was then, however, 

 only of the very simplest kind ; it was probably vegetable 

 life. Probably also the first life appeared in the ocean, 

 though it is not altogether unlikely that it may have 

 begun, and have gone on developing, in fresh water in 

 those great pits which were first formed by volcanoes and 

 which afterwards became lakes and then seas. 



For our purpose, however, it will be sufficient to say 

 that life began in the great bodies of water which were 

 accumulating on the globe, and which owing to the 

 washing down by rain and rivers and stream and 

 wave action of land materials were becoming "salter," 

 or more highly charged with mineral salts of various 

 kinds. The early forms of life were of the nature of jelly- 

 fish, or simple organisms which were permeated by the 

 fluid in which they dwelt. The sea was then warmer 

 than it is now, and there are reasons for believing 

 that it was something above 100 K, perhaps higher 

 perhaps rather hotter than we should now care to bathe 

 in. It was also at the beginning an ocean which was 

 much less salt and had much less lime in it than now. 

 Its water was a good deal "softer." It was, however, 

 becoming much more hard, more like the Dead Sea, 

 which, as everybody knows, is a body of water so 



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