Note 176 — Chapter II

For proof that the mean temperature of the western coast of North America is higher than that of the eastern coast, see Journal of Geograph. Society, vol. ix. p. 380, vol. xi. pp. 168, 216; Humboldt, la Nouvelle Espagne, vol. i. pp. 42, 336; Richardson's Arctic Expedition, vol. ii. pp. 214, 218, 219, 259, 260. This is well illustrated by the botanical fact, that on the west coast the Coniferæ grow as high as 68° or 70° north latitude; while on the east their northern limit is 60°. See an Essay on the Morphology of the Coniferæ, in Reports on Botany by the Ray Society, p. 8, which should be compared with Forry on the Climate of the United States and its Endemic Influences, New York, 1842, p. 89.