ECOLOGY OF WOODLAND PLANTS. 355 
altitude; soils shallow, sandy, dry, in places covered by shallow 
peat and exposed to the prevailing winds; the dominant plants 
are xerophytes, such as Calluna Erica, Vaccinium Myrtillus, 
Deschampsia, &c. 
(3) Lower Coat-Mrasure AnEA.—A lower lying zone with 
soils deep, often covered by much humus and generally moist ; 
the vegetation less exposed and mesophytic in character. The 
dominant plants of the undergrowth of the woodlands are Holcus 
mollis, Pteris aquilina, Scilla festalis, &c. If we keep strictly 
to the geological divisions, we find that the more elevated 
portions reach upwards of 1100 ft., and have soil conditions and 
climate favouring the development of xerophytes, and so bringing 
it within the ericaceous zone. 
These three zones correspond nearly, but not quite, to the 
Moss Moor and the regions of Oat and Wheat cultivation 
respectively, indicated by Smith & Moss (88). The lower part 
of the Millstone-Grit plateau lies within the region of Wheat 
cultivation, while the elevated parts of the Coal-Measure area 
are in the region of Oat cultivation ; though it is interesting to 
note that here Wheat cultivation is frequent though very much 
less so than formerly, economie conditions being in no small 
degree responsible. 
As already stated, the rainfall and temperature vary con- 
siderably in the three zones, and below are given such obser- 
vations as are available. 
Rainfall. 
Records of rainfall for a long series of years are not available 
for the exact areas required for our purpose; but for a limited 
period (1890-1901) records are published for several parts of 
the Moss Moor :— 
Wessenden Head...... 1270 feet. 45:94 inches. 
Harden Moss ........ 1212 ,, 4677 ,, 
Deerhill ............ 1149 ,, 4477. , 
Butterley (11 years) .. 1110 ,, 41:58  , 
No records are available for the higher altitudes. 
For the upper part of the Millstone-Grit arga, three miles to 
the east of the Moss Moor, the averages are :— 
Blaekmoor Foot ...... 800 feet. 42:16 inches. 
Meltham Grange ...... 850 ,, 4031  ,, 
For the Coal-Measure area the available records are just 
