240 Forestry Quarterly. 



vail in literature. It is not, like the Eastern extension, mainly a 

 limestone formation, but, as far as exjDlored, namely for over 40 

 miles of shoreline, and probably beyond it represents a solid granite 

 mountain, a tremendous uplift of syenites, diorites, diabase and 

 other granitic varieties, exposing the original base of the island, 

 which elsewhere is mostly covered up by the limestone deposits. 

 Only in two very confined localities close to the shore was a lime- 

 stone deposit of small extent found, and conglomerates and shales 

 which are also credited as occurring here were seen nowhere. It is 

 for this reason that the contours, although bold, are so much smooth- 

 er and rounder than those of the eastward slopes, which are ter- 

 raced, frequently with vertical sides, a difference which has been 

 observed by those who have described the shores from passing them 

 by steamer. The soils are, therefore, also of different composition 

 from those of most other parts of the island, namely lacking in lime, 

 and, as far as edaphic factors influence it, the character of the flora 

 must differ. Moreover, this range lies with its crest mostly above 

 the 3500 foot level which it attains within fifteen to twenty miles 

 of the shore, many of its peaks reaching above 4000 feet. The high- 

 est peak of the island. El Turquino, which, however, does not lie in 

 the main crest but on a forward spur toward the sea, is supposed to 

 reach an altitude of between 8300 and 86OO feet; the latter figures 

 being noted on the general chart of the coast by our Hydrographic 

 Office. This altitude, also, not only must influence the flora of the 

 alpine region directly, but modifies the climate of the lower levels, 

 and hence must have an influence on the distribution of species. 



The climate, is, of course, in the main similar to that of the rest 

 of the island, namely warm and moist, but the mountain range modi- 

 fies it perceptibly, especially on the Southern slope, since the pre- 

 vailing wind, — the North Eastern Trade — is not only tempered but 

 deprived of its humidity by precipitation on the windward side of 

 the higher ranges. As a result, aided by the Southeasterly seawinds 

 in early spring, the rainy season which on the North side is described 

 as only one, from May to October, becomes here distinctly two, 

 namely March, April, May, as a result of the Southeasterly winds, 

 and again in October, an overflow of the Northern rains, the three 

 months intervening having only occasional short showers, such as are 

 experienced during the rest of the year. 



The temperature, which on the island in general is characterized 

 by a high average and small range — 77° for the mean, and 10° for 



