[66] Draba aretoides has been found on Chimborazo at 16,000 feet.

[67] Poa annua grows at an elevation of 7400 feet.

[68] Aristotle, "Hist. Animal.," i. 9.

[69] Pliny, "Hist. Nat.," xi. 52.

[70] Pliny, "Hist. Nat.," xxx. 7, 12, 24.

[71] Pliny, "Hist. Nat.," xi. 36.

[72] Newman, "Introduction to the History of British Insects."

[73] Ptolemæus, "Syntaxis Mathematicalis," iii. 3.

[74] Certain astronomical calculations, so called because begun under the patronage of Rudolf II., Emperor of Germany (1576-1612).

[75] Kepler, "Astronomia Nova, seu de Motibus Stellæ Martis," p. 53 (ed. 1609).