ing room was provided for him, adjoining his sleeping quarters.
Milli occupied quarters nearby.

Within a week he had mastered enough of the language of these people,
for their strange history began to be intelligible to him.

In spite of the fact that the air here was at merely atmospheric
pressure, nevertheless this place was one mile beneath the surface of
the Pacific. Milli and her people lived in a city hollowed out of a
reef of rocks, reinforced against the terrific weight of the water and
filled with laboratory-made air. They had never been to the surface of
the sea.

The fish with the human arms were their creators and their masters.

Professor Osborne had been right. The fish of the deep, having a head
start on the rest of the world, had evolved to a perfectly
unbelievable degree of intelligence. Centuries ago they had built for
themselves the exact analog of George Abbot's bathysphere, and in it
they had made much the same sort of exploring trips to the surface
that he had made down into the deeps. But their spheres had been
constructed to keep in, rather than to keep out, great pressure.

Their scientists had gathered a wealth of data as to conditions on the
surface, and had even seen and studied human beings. But their
insatiable scientific curiosity had led them to want to know more
about the strange country above them and the strange persons who
inhabited it. And so they set about breeding, in their own
laboratories, creatures which should be as like as possible to those
whom they had observed on the surface.

* * * * *

Of course, this experiment necessitated their first setting up an
air-filled partial vacuum similar to that which surrounds the earth.
But they had persisted. They had brought down samples of air from the
surface of the sea, and had analyzed and duplicated it on a large
scale.

Finally, through long years, they had so directed--and controlled the
course of evolution, in their breederies, as first to be able to
produce creatures which could live in air at low pressures, and then
to evolve the descendants of those creatures into intelligent human
beings.

Some of the lower types of this evolutionary process, both in the
direct line of descent of man, and among the collateral offshoots, had
been retained for food and other purposes. Abbot, with intense
scientific interest, studied these specimens in the zoo of the
underwater city where he was staying