Nature and formation of soils. 27 



of the washing out of loose material, and of tlie cutting 

 power of water; of the abrasion performed hv gravel, 

 pebbles, and stones. 



(r) Transportation Power of Water. — Why is one 

 stream clear and another muddy? Note any sand or 

 soil dropped by water. 



( (/) Note evidences of assorting power of water. 

 Draw a section of the bank of a stream, showing strati- 

 fication. 



(e) Note evidences of underground streams, of land- 

 slides, and describe and explain. 



(/) Frozen Water. — Note work of frost, ice, glacier, 

 and snowslides. 



III. Organic Life. 



Everywhere myriads of living forms abound 

 — in the air, in the water, on the land, and in 

 the soil. However, there must have been a 

 time when life did not exist upon the earth. It 

 must have begun in a very humble manner, be- 

 cause the early conditions were such that com- 

 plex organisms could not exist. 



It is believed by both geologists and embry- 

 ologists that from these simple beings have 

 evolved in succession, through vast ap"es of 

 time, all the higher and more complicated 

 forms. 



With the advent of life arose a new^ and 

 mighty potency in the work of soil formation, 

 and this force becomes the greater as life be- 

 comes more varied and complex, 



I. Plant Life. — The fact that plants have 



