In spite of an easy, readable style, the author cannot quite escape the professorial touch, and I see the book, primarily,as collateral reading for students of biology, psychology and philosophy. This biologist looks at man and studies him in various phases of activity, his reactions, how he meets various social problems, what makes him tick. Man, the highest expression of the animal world, has not taken the precaution of breeding superior men. In most states sterility laws are not enforced, morons and imbeciles continue to have children and fill institutions. All of this has been said before, but this is a pleasant restatement and review of man's behaviour. The author is the Professor of Zoology, University of Wisconsin.