GENESIS OF THE SOIL AND ITS POSSIBILITIES 199 



The ultimate composition of the mold is illustrated 

 in the following table which shows the character of the 

 layers at one, two and three feet in depth : 



Depth Carbon Hydrogen Nitrogen Vegetable matter 



and moisture 

 % % % % 



1 foot.... 57.67 4.48 2.24 90.60 



2 feet.... 47.07 5.15 1.40 72.00 



3 feet.... 8.52 0.53 0.31 15.00 



In this sample, the mold was only three feet deep, 

 resting on pure sand. As the bottom of the de- 

 posit is approached the admixture of sand becomes 

 greater and the percentage of organic matter less. 



No reliable estimate of the time which has been re- 

 quired to form these deposits can be given, but in the 

 Okeechobee region in Florida the deposit of vegetable 

 mold in some places exceeds ten feet in depth. 



The purest vegetable or peat soils contain only small 

 quantities of potash and phosphoric acid, and espe- 

 cially is this true of the Florida deposits which have 

 been formed of vegetable growth containing very little 

 mineral matter. 



It is not at all probable that the flora now growing 

 on any particular area of virgin peat contains all the 

 plants that have contributed to its formation. The 

 principal vegetable growths now going to make up the 

 peat soils of Florida are the following: 



Common names. 



Saw grass Fern brake 



Yellow pond lily Mallow 



Maiden cane grass Broom sedge 



Alligator Wampee Arrow Weed 



Sedge 



The above are only the plants growing in the great- 



