Note 9 — Chapter V

See Zoological Remarks to Captain Back’s Expedition, by Dr. Richardson. He says, “The subsoil north of latitude 56° is perpetually frozen, the thaw on the coast not penetrating above three feet, and at Bear Lake, in latitude 64°, not more than twenty inches. The frozen substratum does not of itself destroy vegetation, for forests flourish on the surface, at a distance from the coast.”