ii(t (OWA ACADKMV Of SCI FACES. 



These tertiarv str;it:i oiit-t-rop in the rjiviiics throu^-hout the 

 ridge wherever erosion has removed the ([uaternarv deposits. 

 and also, in a measure, may be seen throuirhout tlie ridge at 

 its foot, partieuhirly along the eastern portion of the south- 

 ern half and the western portion of the northern half. Aside^ 

 from the Iffiss deposits the soils of t!ie ridge are noted for th<^ 

 amounts of silieious matter, ineluding sands which they eon- 

 tain, and for the paucity of lime in the form of the carbonate. 

 Except in the cas<' of the pine — Pinus mili.s — the tree flora 

 does not respond, in an^' certain measure to this chemic con- 

 dition of the soil. The ridge is botanically interesting as fos- 

 terinsf the orowth of a few tree-forms found nowhere else in 

 the State of Arkansas, though al)undant in other .States in 

 similar and likewise in diverse soils. 



Of the Comferre only the short leaved pine — Piiiufi mttis — 

 and the cypress occur. North of the Arkansas Prof. F. L. Har- 

 vey reports the occasional occurrence of the "old-field pine" 

 — Pinus tfvda — but it is confined mainly to the suital)le areas 

 south of that stream and is never conspicuous north. Only 

 the common short leaved form may be seen at any point north 

 of Helena. In connection with this form it may l)e observed 

 that the distribution of trees in eastern Arkansas is deter- 

 mined more by the general uniformity of soils and topo- 

 graphic features [)resented than by any niarked differences in 

 climatic influences. This species is found mainly, on sandy 

 or gravelly ridges and is confined almost solely to the high- 

 est portions of Crowley's ridge, though small areas, as narrow 

 sti'ips, are found along the White River, l)ut mainly south of 

 the latitude of St. Francis County. North of that latitude 

 the pines do not, as a rule, descend to the bottom lands at all. 

 On these highest ridges there is a thin covering of quater- 

 nary soils, mixed with varying quantities of tertiary sands 

 and clays. It is, as a whole, a highly silieious sod, of no 

 possible agricultural value when the forests shall have been 



