Evolution

The Earliest Europeans

The Intelligent Creation of Life

The Effect of External Influences upon Development

Hung Like An Argentine Duck: A Journey Back In Time To The Origins Of Sexual Intimacy

On the Origin of Species By Means of Natural Selection

Curvology

A New Human

Degeneration: A Chapter in Darwinism

Illogical Geology, the Weakest Point in the Evolution Theory

The Butterfly Hunter

Humanology

The Evolution Controversy in America

Darwinism and Race Progress

Evidence as to Man's Place in Nature

The Meaning of Evolution

The Theories of Darwin and Their Relation to Philosophy, Religion, and Morality

Half Hours With Modern Scientists

Science & Cosmic Messengers

American Addresses, with a Lecture on the Study of Biology

The Conditions of Existence as Affecting the Perpetuation of Living Beings