THE GEORGE AND KNYSNA FORESTS. 69 



In the George portion of the coastal plateau granite, Malmes- 

 bury and Bokkeveld series are met with. In Knysna and 

 Humansdorp the dominant area is Table Mountain Sandstone, 

 but strips of Bokkeveld series occur as well as conglomerates, 

 sands, surface clays and gravel. The soils present are those 

 usual to the formations mentioned.. On the upper slopes of 

 the mountain range and the ridges and kopjes of the foothills 

 the soil is usually very shallow, but on the lower mountain 

 slopes and the foothills the soils are deeper, but in hardly any 

 case may they be considered deep. An ironstone pan is 

 frequently present about two feet below the surface. 



Climate. 



The climate is mild. In winter the mountains occasionally 

 are covered with snow ; frosts occur in low-lying depressions ; 

 hail is comparatively rare, as also are thunderstorms. ' The 

 rainfall is usually in the form of light rains falling throughout 

 the year, but more abundant during late summer and spring. 

 Only occasionally do heavy downpours occur. 



At various centres situated within the area described 

 meteorological observation stations have been established, and 

 from some of these the following data have been obtained. 



The average annual rainfall on the foothills and coastal 

 plateau is : — 



Town of George: 1 station (10-year period), 37.47 in. with 

 115 wet days. 



District of Knysna: 5 stations (10-year period), 41.54 in. 

 with 100 wet days. 



TZitzikama: 3 stations ( 10-year period), 47.42 in. with 113 

 wet days. 



The rainfall fluctuates, as will be observed from the follow- 

 ing figures obtained from Bufrels Nek — elevation 2,200 feet, 

 Lat. 33 53' S., Long. 23 10' E., for period 1894 to 191 1 : — 



47.34", 39.25", 52.31", 45.88", 44.26", 37.59", 41-82", 52.61", 

 60.83", 4i.6i", 51-02", 65.50", 52,34", 36.37", 5378", 50.73". 

 43.22", 45.63". 



The area is subject to warm, desiccating winds from 

 north and north-west, which occasionally blow with considerable 

 force. These winds may last for a few hours or continue for 

 three days — usually they are followed by rain. If long-con- 

 tinued the vegetation becomes inflammable, and frequent veld 

 and forest fires occur. The most disastrous fire, causing con- 

 siderable destruction of forest, was that of February, 1869. 



■ Vegetation. 



The vegetation is divisible into two main classes of wood- 

 land, namely, the sclerophyllous woodland characteristic of the 

 south-west, and consisting, for the most part, of sclerophyllous 

 evergreen woody plants and high forest. The high forest occurs 



