60 A NEW FLOKA OF 



the juniper ascends to 900 yards, the rowan almost as high, the 

 Scotch fir, birch, raspberry, ash, hazel, gale, aspen, Rosa villosa, 

 spinosissima, and several willows, to 500 yards and upwards, 

 500 yards under the northern latitude being more than equiva- 

 lent to 600 yards with us. The following table, therefore, must 

 be considered with this qualification. It shows the number of 

 species which we have observed at the different altitudes, and 

 we give also, for each leap of 100 yards up to 600 yards, a list 

 of a dozen common plants which disappear there. 



In Northumberland and Durham there are below 150 yards 882 species. 



„ „ at 150 „ 581 „ 



„ „ at 200 „ 541 „ 



,, ,, at 250 ,, 495 ,, 



„ ,, at 300 ,, 450 ,, 



„ ,, at 350 „ 407 „ 



„ ,, at 400 ,, 375 ,, 



,, ,, at 450 ,, 326 ,, 



,, „ at 500 „ 300 „ 



,, ,, at 550 ,, 212 „ 



„ ,, at 600 „ 135 ,, 



,, ,, at 650 ,, 108 ,, 



,, ,, at 700 ,, 6Q ,, 



,, „ at 750 ,, 54 ,, 



„ at 800 ,, 34 „ 



,, ,, at 850 ,, 20 ,, 



Total number of species of Lower zone 920 



,, „ Middle ,, 418 



,, ,, Upper ,, 108 



Stop upwards at 100 yards. — Thalictrum flavum, Coronopus 

 Ruellii, LytJirum salicaria, Heliosciadium nodiflorum, Bryonia 

 dioica, Convolvulus arvensis, Nepeta cataria, Ballota nigra, Ery- 

 th(Ra centaurium, Tamas communis, Pulicaria dysenterica, Hordeum 

 pratense. 



Stop upwards at 200 yards. — Lefidium campestre, Papaver 

 Rheas, Barlarea vulgaris, Malva sylvestris, Epilohium Itirsutum, 

 Eupatorium cannahinum, Linaria vulgaris, Lamium album, Liilios- 

 permum arvense, Rumex conglomeratus, Ophioglossum vulgatum, 

 Trifolium arvense. 



