338 GEOGRAPHICAL BOTANY. 



in summer, and 27 in the autumn. Average number of 

 rainy days =140. The prevailing wind is the south- 

 west, the next is the north-east. 



3. Climate of Garonne, or south-west of France^ as 

 far as the Pyrenees. The eastern boundary is situated in 

 Auvergne, but cannot at present be accurately defined ; 

 it probably includes the plateau of Auvergne, and follows 

 the course of the Rhone and Saone. Mean temperature 

 =: 12 7 C. Difference between summer- and winter- 

 heat =: 160 C. ; on account of the smaller extent of the 

 coast-line, the marine climate is less developed here than 

 in the north-west ; mean summer- temperature = 20 6 C., 

 winter-temperature = 5 C. Greatest intensity of cold .at 

 Poitiers, La Rochelle, Toulouse, and Agen, where it 

 attains to 1 2 C. Average amount of rain =586 mm.; 

 of which, 25 p. c. fall in winter, 21 in spring, 23 in 

 summer, and 34 in autumn. Average number of rainy 

 days = 130. The prevailing wind is thje south-west, 

 which in the neighbourhood of the Pyrenees passes into 

 the west. 



4. Climate of the Rhone, comprises the valley of the 

 Rhone, from Dijon and Besancon to Viviers, and the 

 mountainous regions of the Higher Alps ; the boundary 

 in the department of the Lower Alps is at present unde- 

 fined. Mean temperature = 11C. Difference between 

 summer and winter = 18 6 C. Mean temperature of 

 summer = 21 3 C., of winter 2 5 C. Average quantity 

 of rain = 946 mm., i. e. the greatest amount precipitated 

 throughout the whole of France ; of which 20 p. c. falls 

 in the winter, 24 in the spring, 23 in the summer, and 

 34 in the autumn. Number of rainy days in the valley 

 of the Saone = 120-30, in the valley of the Rhone = 

 100-15. Prevailing winds, north and south. 



5. Mediterranean climate. The northern boundary 

 runs through the Rhone at Viviers, near Montelimart, 

 thence follows a line drawn on one side to Montpellier, 

 on the other to Marseilles, and, lastly, comprises the coast- 

 districts of Provence and the regions of Aude as far as 



