ABSTRACT
“THE Development Hypothesis” (item 113) and “A Theory of Population” (item 114) mark Spencer’s foray into biology. His later book, The Principles of Biology (item 17), with which many of the materials making up this chapter are concerned, is inclusive of zoology and botany, as well as their various subdivisions. With the publication of the second edition of First Principles (item 16) and the second volume of his treatise in biology in 1867, Spencer forbade his publishers to send copies of his books to any of the periodical reviews. He was aggrieved by their careless treatment of his earlier works, and he held to his refusal to provide review copies for nearly ten years. Had Spencer not interdicted the review process, much more would have been written about the second volume of the first edition of The Principles of Biology, the second and third editions of First Principles, the second edition of The Principles of Psychology (item 18), and the third series of Essays (item 33).
