The Variation of Animals and Plants under Domestication was published by John Murray in two volumes in January 1868. Darwin called it his “big book” — the detailed exposition of the evidence for variation and inheritance that The Origin of Species had only sketched. The first volume covers specific groups of domesticated animals and plants: pigeons (Darwin’s favorite experimental subjects), dogs, cats, horses, cattle, sheep, rabbits, goldfish, silk moths, and a vast array of cultivated plants. The second volume addresses the general principles of variation, inheritance, hybridization, and selection.
The pigeon chapters are among Darwin’s finest scientific writing. He kept and bred dozens of varieties of fancy pigeons — pouters, fantails, tumblers, carriers — and used them to demonstrate that all domestic pigeon varieties descended from a single wild species, the rock dove (Columba livia). The range of variation produced by selective breeding was enormous: pouters with inflated crops, fantails with thirty tail feathers (the rock dove has twelve), tumblers that somersaulted in flight. If human breeders could produce such diversity in a few centuries, Darwin argued, natural selection acting over millions of years could produce the diversity of life.
The book’s most speculative section is Darwin’s “provisional hypothesis of pangenesis” — a theory of inheritance in which every cell in the body sheds tiny particles called “gemmules” that collect in the reproductive organs and are transmitted to offspring. Pangenesis was wrong (Mendel’s particulate inheritance, published in 1866 but unnoticed, was the correct answer), but Darwin’s willingness to propose a testable mechanism for inheritance demonstrated his commitment to explanation rather than mere description.
Collecting The Variation of Animals and Plants
First edition (John Murray, London, 1868): Two volumes, green cloth binding.
Market values:
- First edition, two volumes, fine: $3,000–$8,000
- Very good: $1,000–$3,000