THE AZORES 



367 



their base and comes to rest. To the people of the coast villages, 

 especially of that of Terra do Pao, which lies immediately beneath 

 the bluffs, the bombardment by boulders is a matter to be reckoned 

 with. They pointed out some to me which they declared had come 

 from the upper slopes of the peak. One of them was about three feet 

 high, and I was told that this size may be much exceeded. These rock- 

 masses, after leaping and bounding for at least 4000 or 5000 feet 

 down the steep mountain sides, sometimes come crashing down 

 into the precincts of the village in the middle of the night. 



The Extent of the Vegetation on the Mountain of Pico. — 

 The impression formed at a distance that the lower two-thirds of 

 the mountain are vegetated and that the lava slopes of the upper 

 third are barren, is verified only in a relative sense when the observer 

 ascends the mountain. Godman (p. 15) remarks that " in winter 

 the extreme cone is frequently covered with a thin layer of snow, 

 and is destitute of vegetation with the exception of a few lichens." 

 Ogilvie-Grant, speaking of the Magdalena side of the mountain, 

 states that on the higher slopes " desolation and lava covered with 

 grey lichen and moss hold undisputed sway " (Nov. Zool., Jan. 1905). 

 Impressions of this kind are often acquired by those who have not 

 made the complete ascent. 



The lower slopes are generally well vegetated up to altitudes of 

 4500 to 5000 feet, moor and grass land predominating in their higher 

 levels, that is, above 2000 feet. Woods are well developed in places, 

 the lower woods on the western side and the upper woods on the 

 south-eastern side. On the north-west side there is an almost 

 continuous band of wood, which extends from the vicinity of Ban- 

 deiras, about 400 feet above the sea, right up the mountain slopes 

 to over 5000 feet, where the trees and shrubs are dwarfed. The 

 woods are essentially formed by evergreen shrubs and trees; but 

 on account of the persistent agency of the woodcutter through 

 centuries the trees, except when specially preserved, rarely exceed 

 twenty feet in height, and are usually not more than fifteen or sixteen 

 feet. Dwarfing of the trees and shrubs begins as a rule at about 

 4000 feet as the effect of deficient soil and of exposure to the prevailing 

 strong winds; but it is likely that in the early times forests of 

 considerable height existed at this altitude. 



Above the level of 5000 feet the sparse vegetation of the pre- 

 cipitous upper third of the mountain presents a great contrast to 

 the grassy and wooded slopes below. On the crumbling lava and 

 on the beds of cinders and coarse ashes that form the surface plants 

 for the most part obtain a scanty hold. It is true, however, that 

 dwarfed trees and shrubs climb the steep slopes for a few hundred 

 feet, the scrub failing at levels short of 6000 feet; but above that 

 height vegetation is sparse, and the plants become scarcer and scarcer 

 as one nears the summit, about half a dozen species reaching in 

 much diminished numbers the terminal crater and its small cone. 



The Zones of Vegetation on the Mountain of Pico. — When 

 the writer visited Pico with the object of determining the altitudinal 

 arrangement of the plants, he was only acquainted with Watson's 

 and Trelease's monographs, issued respectively in 1870 and 1897. 



