ST. 7AGO. 
39 
speaking, must have elapsed since the most recent changes—such, for example, as those 
which may be studied in the cliffs of Porto Praya. The considerable and successive alterations 
of level of which they bear evidence, as well as the effects of denudation everywhere visible 
on the island, and which have even effaced the ancient craters whence the lava streams 
PORTO PRAYA, ST. JAGO. 
proceeded, show that the time required to form the harbour where the “ Challenger ” lay 
sheltered can never be measured by the limited scale of years at the command of our 
imagination. 
The capital of the Cape de Verde Islands is situated on a projecting bluff, isolated from 
the surrounding hills by a ravine which, with its grove of palm-trees, joins the harbour on 
V 
both sides of the town. Beyond stretches the same desert of stones and sand and barren hills 
with which St. Vincent had made us acquainted. Some districts, however, which enjoy the 
advantage of a running stream, permit the cultivation of the cocoa-palm, the sugar-cane, and 
other products of a tropical climate. An excursion was made to one of these oases, occupied 
by the village of Trinidad, a few hours’ ride from Porto Praya. The road leads through a 
stony valley, with a patch here and there of almost leafless shrubs. A short distance from 
the town stands a baobab tree, mentioned by former travellers, and said to be more than a 
thousand years old. Its trunk measures forty-two feet in circumference, and it is the last 
survivor of the trees which, according to tradition, at one time adorned the neighbourhood of 
Porto Praya. Another of these patriarchs of vegetation stands in the village of Trinidad. 
We noticed on this occasion several flocks of guinea-fowl, but, as in Dr. Darwin’s time, they 
proved too wary for our sportsmen ; also a kingfisher, with bright blue and yellow plumage. 
H.M.S. “Challenger” sailed from Porto Praya on the 9th August. Her cruise along 
the African coast was marked by several magnificent displays of phosphorescence. One 
evening the ship traversed what was literally a sea of light, almost dazzling to the eye. We 
found that the light proceeded from an animal known to the naturalist under the name of 
Pyrosoma. It consists of a semi-transparent cylindrical mass, slightly tapering towards one 
end, about one inch in diameter, and from three to four inches long. On a subsequent 
F 
