Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne (1867).djvu/65

Rh {|
 * || | &emsp; ||
 * Saxifraga oppositifolium.||Juncus squarrosus.
 * Oxalis acetosella.||  triglumis.
 * Chrysosplenium oppositifolium.||Carex stellulata.
 * Galium saxatile.||  rigida.
 * Sedum rhodiola.||Anthoxanthum odoratum.
 * Sausserea alpina. ||Poa annua.
 * Hieracium chrysanthum. ||Festuca ovina.
 * Campanula rotundifolia.||Aira flexuosa.
 * Vaccinium myrtillus. ||Allosorus crispus.
 * vitis-idaea.||Lastrea dilatata.
 * Euphrasia officinalis.||  filix-mas.
 * Thymus serpyllum.||Cystopteris fragilis.
 * Rumex acetosa.||Lycopodium alpinum.
 * Oxyria reniformis.||  selaginoides.
 * }
 * Campanula rotundifolia.||Aira flexuosa.
 * Vaccinium myrtillus. ||Allosorus crispus.
 * vitis-idaea.||Lastrea dilatata.
 * Euphrasia officinalis.||  filix-mas.
 * Thymus serpyllum.||Cystopteris fragilis.
 * Rumex acetosa.||Lycopodium alpinum.
 * Oxyria reniformis.||  selaginoides.
 * }
 * Thymus serpyllum.||Cystopteris fragilis.
 * Rumex acetosa.||Lycopodium alpinum.
 * Oxyria reniformis.||  selaginoides.
 * }
 * Oxyria reniformis.||  selaginoides.
 * }

The following are the principal species which are conspicuously more frequent amongst the Lake hills than in the east, those marked with a star not being Northumberland, Durham, or North Yorkshire plants at all.

Zones of Altitude.—The difference in mean annual temperature between the equator and line of perpetual snow is about 55° Fahrenheit, which is a lowering of rather less than one degree of temperature to a degree of latitude. On the equator at sea-level