have been much reduced by the general disturbance of conditions,
the record is poor. Molluscs and Brachiopods and small fishes fill the
list, but are of little instructiveness for us, except that they show a
general advance of species. Among the Cephalopods, it is true, we find
a notable arrival. On the one hand, a single small straight-shelled
Cephalopod lingers for a time with the ancestral form; on the other
hand, a new and formidable competitor appears among the coiled-shell
Cephalopods. It is the first appearance of the famous Ammonite, but
we may defer the description of it until we come to the great age of
Ammonites.

Of the insects and their fortunes in the great famine we have no direct
knowledge; no insect remains have yet been found in Permian rocks. We
shall, however, find them much advanced in the next period, and must
conclude that the selection acted very effectively among their thousand
Carboniferous species.

The most interesting outcome of the new conditions is the rise and
spread of the reptiles. No other sign of the times indicates so clearly
the dawn of a new era as the appearance of these primitive, clumsy
reptiles, which now begin to oust the Amphibia. The long reign of
aquatic life is over; the ensign of progress passes to the land animals.
The half-terrestrial, half-aquatic Amphibian deserts the water entirely
(in one or more of its branches), and a new and fateful dynasty is
founded. Although many of the reptiles will return to the water, when
the land sinks once more, the type of the terrestrial quadruped is now
fully evolved, and from its early reptilian form will emerge the lords
of the air and the lords of the land, the birds and the mammals.

To the uninformed it may seem that no very great advance is made when
the reptile is evolved from the Amphibian. In reality the change implies
a profound modification of the frame and life of the vertebrate. Partly,
we may suppose, on account of the purification of the air, partly on
account of the decrease in water surface, the gills are now entirely
discarded. The young reptile loses them during its embryonic life--as
man and all the mammals and birds do to-day--and issues from the egg a
purely lung-breathing creature. A richer blood now courses through the
arteries, nourishing the brain and nerves as well as the muscles. The
superfluous tissue of the gill-structures is used in the improvement of
the ear and mouth-parts; a process that had begun