valuable has been contributed to geological science by these more recent
investigations, and many changes have been made in nomenclature and other
points of detail, it is interesting to find that all the chief facts
described by Darwin and his friend Professor Miller have stood the test of
time and further study, and remain as a monument of the acumen and accuracy
in minute observation of these pioneers in geological research.

JOHN W. JUDD.



CHAPTER I.--ST. JAGO, IN THE CAPE DE VERDE ARCHIPELAGO.

Rocks of the lowest series.
A calcareous sedimentary deposit, with recent shells, altered by the
contact of superincumbent lava, its horizontality and extent.
Subsequent volcanic eruptions, associated with calcareous matter in an
earthy and fibrous form, and often enclosed within the separate cells of
the scoriae.
Ancient and obliterated orifices of eruption of small size.
Difficulty of tracing over a bare plain recent streams of lava.
Inland hills of more ancient volcanic rock.
Decomposed olivine in large masses.
Feldspathic rocks beneath the upper crystalline basaltic strata.
Uniform structure and form of the more ancient volcanic hills.
Form of the valleys near the coast.
Conglomerate now forming on the sea beach.

(FIGURE 1: MAP 1: PART OF ST. JAGO, ONE OF THE CAPE DE VERDE ISLANDS.)