NIGER EXPEDITION. 87 
within the last very few hundred years; and hence, with the 
North Cape and Cape of Good Hope, they constitute the 
three salient points in the geography of the eastern Atlantic. 
In many of their physical features, they form a continuation 
of the great Sahara desert, that mysterious blank on our maps, 
upon whose sea of sand so many of our venturous countrymen 
have embarked, to be heard of no more. The hitherto unex- 
Plored mountains of the Cape de Verds rise 8000 feet and 
upwards above the sea, in serried ridges and isolated peaks; 
Promising a rich harvest to some Botanist, who may in those 
higher and cooler parts of the islands rely on immunity from 
disease and a temperate climate. There he may expect to find 
new types of plants; for the Mountain Flora of Western 
Tropical Africa is wholly unknown; and of its probable 
nature even we can form no guess. To conclude, the Lin- 
nan axiom of “semper aliquid novi ex Africa" has never 
yet proved false. A Naturalist cannot see the shores of that 
continent without feeling that no other spur is required to 
exertion, in a field to which such a motto still applies with 
80 much force, 
