168 WHAT IS LIFE? 



nucleoius appears, and has continued to appear. It 

 may be considered simply as a mass of nervous matter, 

 exciteable, that is sensitive, to light, to heat (i.e. Ether), 

 and amenable to the other forces in Nature. Simply 

 a mass of molecules, every one of which is alive. 



Geologists divide the crust of the earth into five great 

 groups, which we may, in order to avoid technical 

 detail, classify thus : 



L Ante-primary Rocks. 



2. Primary Rocks. 



3. Secondary Rocks. 



4. Tertiary Rocks. 



5. Post-tertiary Rocks. 



The strata of the primary and subsequent rocks are 

 subdivided into a number of local divisions. All these 

 rocks were originally laid down by means of water in a 

 more or less horizontal manner, frequently in oceans or 

 seas. We put some sand in a bottle of water, shake it 

 up, and we find the coarse particles fall the first, the finer 

 after, and the finest last. And so are strata formed by 

 the finer particles floating to the depths of the ocean 

 and the coarser particles deposited near the sea-shore. 

 But the deposits as a whole are placed horizontally ; 

 it is as if Nature tried to deposit by the spirit level. 

 Simple as the experiment with the bottle is, it illus- 

 trates the basis of all the phenomena in Nature as 

 regards the original deposition of a very large mass of 

 the material of which the earth's surface is formed. 



Now below all these stratified formations there are 

 huge formations, called the ante-primary rocks. These 

 formations include the great bulk of " igneous " and 

 " metamorphic " rocks. Many " metamorphic " rocks 

 appear to be in a transition state between the igneous 



