PLANTS INDICATING SUBSOIL. 



163 



Nice it may be sought for in vain and is onh' 

 to be met witli occasionally at Cannes. 

 As the Cork Oak woods of the Mon- 

 tagnes des Maures betra\- the primitive 

 /^ A/ji^ rock of the range, so other 

 WJf tM/fi/^J? pl^^'s indicate the limes- 

 tone =of the adjacent Alps. 

 -_»,^'' Sometimes solitary- patches 



of rock maA' be recognised b\' 



their vegetation. Thus a few 



\ears ago the Inspector of Woods 



and Forests at Saint A'enant, in 



the forest of Orleans, noticed 



:i narrow strip of calcareous 



plants about half a mile long, 



would 

 all its 

 curious 

 ation 



whereas the remaining llora of 



the wood indicated silicious soil. 



He was led b^' this obser\'ation 



to dig, and at no great depth he 



disco\'ered an old Roman road 



oaved with limestone, — The Cork 



'aks of the Montagues des Maures 



are stripped during the summer, when 



not onh' the trunk but also the thicker 



branches are peeled ; but this is always 



restricted to certain parts, for it 



be injurious to the tree to deprive it of 



bark at once. The bared portions present the most 



appearance, for immediateh' after the oper- 



the\' are iiesh-coloured but gradualh' become 



