82 

 dunes, except the particles are larger, f.ncL the developiient of 

 vegetation is probabl/ the same. Kaxne flora prohably originated 

 in glacial times. If a Ilarae got Id "be denuded we would find the same 

 suGcessian of flora as that on a heach. On a sand hill there is 

 a long period hetwe^^n youth and maturity because sand does not 

 readily retain water and humis accumulation is slow. A clay hill 

 is just the opposite, and also erodes more rapidly. On the hills 

 in this region chestnut oaks and chestnuts are ifoAv the laost dominant 

 trees. Pinus rigidus was prohalDl;- the first, folloved by Q,uercus 

 nigre and Ca^tanea the first of which was replaced by Robihia. 



It is difficult to determine what the fut\ire will be. Beeches 

 and maples are xerophytic and are fo\ind to some extent at foot of 

 the hills. They represent a later stage than the chestnut. 

 3. Rock Hills . 



Lichens are the first plants found on rock hills. Granites 

 are best adapted to lichen growth since the different constituents 

 decay unequally giving rise to crevices which allow the plants to 

 gain a foothold. Limestone and sandstone are less well adapted 

 owing to their rapid disintegration. Lichens are .followed by 

 crevice plants especially mosses an* some of the pinks. 



B. "nirection o£ S_lQjDe. 

 The sun is s-.ich an Important factor that in spite of tlio direction 

 of prevailing wonds, the north slope is always the Moistest. 

 Moisture and wind are most important factors in determining the slope 



of a hill. 



