"Ascidians are marine creatures permanently attached to a support. They
hardly appear like animals, and consist of a simple, tough, leathery sac, with
two small projecting orifices."-MR. DARWIN.

CLAXTON, REMSEN & HAFFELFINGER,
819 & 821 MARKET STREET.

1872.

HARVARD UNIVERSITY LIBRARY

MAR 5 1941

ASCIDIAN TADPOLES.

THE LARGER FIGURE HIGHLY MAGNIFIED.

Given that the reader may form some idea of man's very remote ancestors, according to Mr. Darwin. See page 13.