Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne (1867).djvu/328

310 {| class="wikitable"
 * Vaccinium uliginosum.
 * Ligusticum scoticum.
 * Asplenium germanicum.
 * Lamium intermedium.
 * Carex irrigua.
 * Blysmus rufus.
 * Hieracium argenteum.
 * Mertensia maritima.
 * Callitriche autumnalis.
 * Carex incurva.
 * }
 * Callitriche autumnalis.
 * Carex incurva.
 * }
 * }

7. — Dividing the surface of the two counties into three zones of altitude and climate, as explained already, only thirteen species out of the nine hundred and thirty-five do not grow somewhere in the lower one, whilst four hundred and eighteen species ascend into the middle zone and only one hundred and eight into the highest of the three. Fifty species are essentially restricted to the sea-coast, and forty-five shew a decided preference for the dry-soiled and especially the limestone tracts.