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Lecture 16, August 6, 1900. 

 5i- Soil . 



Scliimper considers soil raost important factor hut fee includes every- 

 thing under the term soil teliich is contained in it, as water, etc. 

 Soil ecologically is that in which a plant can grow. Soil is divided 

 mechanically into 



1. Solid rock . 



Difference in flora in this case depends upon character of rock. 

 Different types of lichens grow on granite, limestone, etc. Lichens 

 a real rock plant, mosses grow more in crevices. Shaly rocks decay 

 so rapidly that lichens find it difficult to grow on them. Sandstone 

 varies. Granite allows iiruch growth, of lichens since the feldspar 

 in it erodes more rapidly than the other elements and gives foothold 

 for the spores. 



2. Residual soil . 



Not found in glaciated re/j;ions, hence not found in Long Island. 



3. - Secondary soils . 



Soils which hegin as residual soils but are transported to ibbher 

 places. Example — Fire Island. All the soil secondary, probably came 

 from Mon-f.auk Point and before that from IT. E. Such soiia represent 

 erosion of rocks ages ago, either by water action, wind action or 

 glacial action. Deposits strictly due to glaciation are usually 

 unstratif ied. Those due to water stratified and coarse. Those due 

 to wind fine and stratified p!l/^ or unstratif ied. Bulk of Long Island 

 'deposits may be ascribed to waters which came from melting ice. 



