Fortunate Islands 
acteristic rock and dry climate plants not found else- 
where. 
At those heights from 1500 feet (or on the S.W. and 
S.E. 2500 feet) to 5000 (or 4ooo on S.W. and S.E. sides), 
where the clouds are still in the habit of resting so as 
to keep fresh and moist the gathering grounds of the 
springs which irrigate the lowlands, the changes have 
been very great. This-is the home of Laurus canariensis, 
of Olives, Rhamnus, Arbutus, Myrica faya and Viburnum. 
It is a strange flora which recalls, perhaps better than 
any other still living, the old Miocene times of Europe 
before the Ice Age disturbed everything. This part hasun- 
fortunately been much altered by the grazing of animals 
and much of it is now covered by those gum-cistus 
heaths which are prevalent in Spain and Portugal. The 
coniferous forest (Pinus canariensis) is also much de- 
stroyed and almost obliterated, yet from 5400 to 7800 
feet occasional pines exist along with bracken, thyme, 
helianthemums, and the common asphodel. Above 
this level, where the influence of the cloud is rarely felt, 
there comes a dry and sunny mountain-desert where 
Spartium nubigenum, Cytisus proliferus, Arabis albida 
and Ephedra may ascend to 9850 feet.’ The last 
flowering plant is the little violet discovered by Von 
Humbolt. 
This, the highest part of Teneriffe, resembles the 
cold dry deserts at great altitudes in Tibet and in Peru. 
The general suitableness of all these various floras to 
their positions on the mountain side is a typical and 
most instructive example of Nature’s workings. 
The way in which the South Sea Islands obtained 
their rich and varied floras is always interesting but by 
no means fully understood. 
It is not always remembered that two things are 
necessary when a desert island has to be colonised. The 
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