II] WOODLAND ASSOCIATIONS 45 



where Quercus Robur is the dominant tree and where Q. sessili- 

 flora is rare. The whole of this area has been mapped by the 

 geological surveyors as consisting of rocks of the Coal-measure 

 series ; but such rocks are here obscured, or partially obscured, 

 by deep deposits of fluvio-glacial sands. There are, unfortu- 

 nately, no geological maps with drift published of any portion 

 of the district ; and, in fact, the Geological Survey has not yet 

 commenced its examination of the drift of this locality. When, 

 however, such maps are published and compared with vegetation 

 maps, they will afford a striking commentary on the differential 

 distribution of the woods of Quercus Robur and Q. sessiliflora on 

 the west of the Pennines in this latitude. 



The region of woods of Quercus Robur of the lowlands of 

 the east of the Pennines does not reach the Peak District, and, 

 in fact, possibly ceases east of Sheffield. 



The woods of Quercus Robur of this district occur at their 

 local, upper altitudinal limit, and have been interfered with by 

 the planting of foreign trees and shrubs, such as laurels and 

 rhododendrons; and they cannot therefore be regarded as 

 typical of such woods in general. Hence it is not desirable to 

 describe them here in detail. Such a description will be a more 

 fitting outcome of a vegetation survey of some portion of the 

 Cheshire plain, where woods of Quercus Robur are more extensive, 

 more numerous, and more typical in character. 



TRANSITIONAL WOODS OF QUERCUS ROBUR AND 

 Q. SESSILIFLORA 



In a few places near the junction of the woods of Quercus 

 Robur and of Q. sessiliftora, some small woods occur in which 

 the two species are found side by side. This is the case, 

 for example, with regard to the small Townscliffe Wood, 

 east of Mellor. Had such woods been extensive enough, their 

 transitional character could have been indicated on the vegetation 

 maps by giving them the ground colour of the woods of Quercus 

 Robur and stippling on this the darker colour used for woods of 

 Q. sessiliflora. However, this course was impracticable owing 

 to the small size of the transitional woods. 



Whilst Quercus Robur and Q. sessiliflora respectively form, 

 as a rule, well-defined associations, it sometimes happens that a 



