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 equivalent 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 | " | 66 | " |
| " | " | 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, Lythrum salicaria, Heliosciadium nodiflorum, Bryonia dioica, Convolvulus arvensis, Nepeta cataria, Ballota nigra, Erythœa centaurium, Tamus communis, Pulicaria dysenterica, Hordeum pratense.
Stop upwards at 200 yards.—Lepidium campestre, Papaver Rhoeas, Barbarea vulgaris, Malva sylvestris, Epilobium hirsutum, Eupatorium cannabinum, Linaria vulgaris, Lamium album, Lithospermum arvense, Rumex conglomeratus, Ophioglossum vulgatum, Trifolium arvense.
