The advance of vertebrates from fish through amphibia and reptiles to
mammals.—The development of skeleton, appendages, circulatory and
respiratory systems, and brain. —Mammals: The oviparous monotremata.
-Marsupials.-Placental mammals.-Development of the placenta.-Prim-
ates.-Arboreal life and the development of the hand.-Comparison of man
with the highest apes.-Recapitulation of the history of man's origin and
development. The sequence of dominant functions.
Mode of investigation.— Intellect. — Sense-perceptions.-Association.—
Inference and understanding.-Rational intelligence.-Modes of mental or
nervous action.-Reflex action, unconscious and comparatively mechanical.
-Instinctive action: The actor is conscious, but guided by heredity.-In-
telligent action.-The actor is conscious, guided by intelligence resulting
from experience or observation.-The will stimulated by motives.—Appe-
tites.—Fear and other prudential considerations.-Care for young and love
of mates.-The dawn of unselfishness.-Motives furnished by the rational
intelligence: Truth, right, duty.—Recapitulation: The will, stimulated by
ever higher motives, is finally to be dominated by unselfishness and love
of truth and righteousness.-These rouse the only inappeasable hunger,
and are capable of indefinite development. —Strength of these motives.—
Their complete dominance the goal of human development.
The reversal of the sequence of functions leads to extermination, degen-
eration, or, rarely, to stagnation.-Natural selection becomes more un-
sparing as we go higher.-Extinction.-Severity of the struggle for life.-
Environment one.-But lower animals come into vital relation with but a
small part of it.—It consists of a myriad of forces, which, as acting on a