This highly educational book comprises a series of essays by the intellectual and scientist Grant Allen, author and novelist, and a successful upholder of many scientific theories. As a scientist Allen was an evolutionist, and as a novelist one of his most persistent themes was the effect of heredity.

Even his lighter and more popular works evidence not only his scientific outlook but also his persistent questioning of established convention and of institutions and officials that uphold it. A walk with him was an education in botany and zoology, and he had no whimsies or quirks; he was always reasonable, good-tempered, vivacious, bright, and interested in every human interest. . . .

He would always like to regulate human life generally as a department of the India Office; and so Sir George Campbell would fain have husbands and wives selected for one another (perhaps on Dr. Johnson's principle, by the Lord Chancellor) with a view to the future development of the race, in the process which he not very felicitously or elegantly describes as 'man-breeding.'