Note 5 — Chapter XI · THE PROFESSOR: AVIGNON (CONTINUED)

Thanks to its isolated position, which leaves it freely exposed on every side to atmospheric influences; thanks also to its height, which makes it the topmost point of France within the frontiers of either the Alps or the Pyrenees, our bare Provençal mountain, Mont Ventoux, lends itself remarkably well to the study of the climatic distribution of plants. At its base the tender olive thrives, with all that multitude of semi-ligneous plants, such as the thyme, whose aromatic fragrance calls for the sun of the Mediterranean regions; on the summit, mantled with snow for at least half the year, the ground is covered with a northern flora, borrowed to some extent from Arctic shores. Half a day’s journey in an upward direction brings before our eyes a succession of the chief vegetable types which we should find in the course of a long voyage from south to north along the same meridian.5