312 Smith and Woodward : Botanical Survey of Teesdale. 



entirely confined to the exposure of the ' Whinsill ' basalt and 

 dolerite, and does not occur higher up the valley. This apparent 

 geological distribution is due, we think, not so much to soil 

 conditions as to the roughness of the whinsill scars which renders 

 them not easily accessible to sheep, and where the heather is 

 rarely burnt. The Juniper has a fairly wide distribution in 

 Britain as regards geological substrata, but like most other 

 shrubs and trees, it has disappeared from most places where 

 grazing and heather burning are in operation. A constant 

 associate of the Juniper here is worthy of notice, namely the 

 wood sorrel [Oxalis acetosella), which occupied the deep-shaded 

 ground beneath the bushes to the exclusion of all other species. 

 As Wiesner and Riibel have pointed out, this is one of the most 

 ■extreme shade endurers among European flowering plants. 



On Widdybank Fell the features of the vegetation so well 

 described by Mr. J. Gilbert Baker in ' North Yorkshire,' were 

 easily recognised. The general tone of the Fell is a dull heathy 

 grassland splashed here and there with bright green grassy 

 patches. Sheep's Fescuegrass, Field Rush (Luzula), and 

 dwarf Sedges seem to form the groundwork of these patches, 

 but quite a number of rare or local species have been recorded 

 from them, including Gentiana verna, which now studded the 

 carpet with its wonderful blue flowers so suggestive of the Alpine 

 ' wiesen ' in early summer. This plant-association coincides 

 with the occurrence of the sugar limestone, and on Widdybank 

 this is derived from several beds of limestone altered by the 

 intrusion of the 'whinsill' (see geological report in The Naturalist, 

 July, p. 268). It was interesting to find below Cronkley Scars 

 a similar patch of vegetation on the Yorkshire side of the Tees, 

 here also on sugar limestone, but this time helow the ' whinsill.' 



This interesting association is therefore developed on peculiar 

 rock soils, and in the main over an unglaciated area. From 

 this point of view it well deserves more detailed study, as the 

 facts seem to indicate that it is a relic of the pre-glacial flora, 

 modified to some extent by later invasions. 



One day was spent by a small party whose mission was on 

 the whole regarded as on a footing with another botanical 

 excursion of which a witty Scottish professor said : 



" Some folk '11 tak' a heap o' fash, for unco little end, man ; 

 An' meikle time an' meikle cash, for nocht ava' they'll spend, man." 



The object was to examine the somewhat inaccessible head- 



Naturalist, 



