80 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
natural timber consists of the upland oaks with some short-leaf pine ; 
along the borders of the region the long-leaf pine also makes its ap- 
pearance wherever the sandiness of the soil increases beyond a certain 
limit. 
The true gneissic soils are perhaps the best for cotton. 
By gradual interchange of constituents, the gneisses grade off into 
the other rocks of this series, and a corresponding variation in the 
quality of the soils is thus brought about. 
By the partial or complete replacement by the mineral hornblende of 
certain of the constituents of the gneiss are produced the hornblendic 
gneisses and hornblendic slates, which, in disintegrating, yield those 
warm, red, loamy soils, with timber of magnificent oaks, making perhaps 
a fourth or less of the lands along the outer border of the region. 
The red soils are considered best suited to the grain crops, though 
they give fine yields of cotton also. 
All the gneissic soils have a reddish, clayey subsoil, and are capable 
of indefinite improvement. 
Through Georgia and South Carolina the gneissic soils form by far 
the larger proportion of the lands cultivated in cotton, as may be seen 
from the percentage map accompanying. 
The clay slates, mica slates, and quartzites of the metamorphic region 
yield soils of inferior fertility, and they are of comparatively little im- 
portance in the cultivation of cotton. 
West of the Mississippi the metamorphic areas are of somewhat lim- 
ited extent, and are comparatively unimportant from our standpoint. 
