ILLUSTRATIONS. 



Eelief map of the Edwards Plateau. (Eighteenth Ept. U. S. Geological Survey 



Pt II, PI. XXIII) Frontispiece 



Plate I. Fig. 1. — View of the timber (mostly cedar) on the white, crumbly 

 limestone; higher remnants of the plateau in the distance. No 

 soil accumulates except under clumps of cedar. Colorado breaks 

 10 miles north of Austin. Fig. 2. — Comal River at its source. 



Escarpment timber 8 



11. Fig. 1. — Characteristic view of the Edwards Plateau forest, on the 

 Colorado River, 10 miles above Austin. Mostly cedar on the sum- 

 mits here. Mountain oak lower clown the sides of the gorge. 

 This timber prevents rapid run-off and erosion after rainfall. Fig. 

 2. — Hill near Austin covered Avith pure stand of mountain oak. 

 On the left the timber has been cut clean for fuel. Such clear- 

 ings show rapid renewal of timber 8 



III. Fig. 1. — View in a cedar brake. The adobe soil and rocks are cov- 



ered Avith a thin layer of brown soil and forest debris, showing 

 capacity of cedar to accumulate soil even on the arid slopes of 

 crumbly limestone. Fig. 2. — -Characteristic occurrence of cedar 

 upon a steep slope covered by loose limestone talus, upon which 

 most vegetation is unable to establish itself. Dry bed of Bull 

 Creek 16 



IV. Fig. 1. — Cedar brake near Austin twenty-five years after first cutting. 



A heavy crop of fuel and charcoal. Shows capacity for reforesta- 

 tion. Fig. 2. — Characteristic encroachment of mesquite on pasture 

 land in central Texas. With the exception of a few scattered 



live oaks, this was a clean prairie a few years ago 24 



V. Fig. 1. — "South gorge" at its head under Lone Tree Hill, near 

 Austin. The higher slopes have been denuded of timber. The 

 run-off water after heavy rainfall is very Adolent. Fig. 2. — ' 'Xorth 

 gorge" from Lone Tree Hill. Heavily timbered slopes. Violence 

 of rainfall broken and rapid run-off prevented 24 



