The Variation of Animals and Plants under Domestication — Volume 2 — Inside the Classic

Reversion as a Window into Latent Characters

Darwin devotes the first chapter to reversion, which he treats as a key to understanding inheritance. He catalogs cases where pure breeds revert to ancestral forms—for instance, pigeons and fowls that throw back to wild coloration—and argues that these reversions prove the existence of latent characters carried in the germ. The germ, he writes, is “a wonderful object” because it contains all the potential traits of both parents and ancestors.

He also examines reversion through bud-propagation and in segments of the same flower or fruit, showing that the phenomenon is not limited to sexual reproduction. A peloric flower, for example, may represent a reversion to an ancestral symmetry. Darwin’s method is to collect diverse instances and then infer a common cause, rather than to propose a mechanism he cannot observe.

Prepotency and the Limits of Inheritance

In the second chapter, Darwin introduces the concept of prepotency—the tendency of certain individuals or breeds to transmit their characters more strongly than others. He notes that prepotency can be stronger in one sex than the other, and that it sometimes depends on whether a character is visible in one breed and latent in the other. This idea helps explain why some crosses produce offspring that resemble one parent almost exclusively.

Darwin also discusses inheritance limited by sex, citing newly acquired characters in domesticated animals that are transmitted by only one sex, or lost by only one sex. He connects these observations to the principle of inheritance at corresponding periods of life, which he argues is crucial for embryology. The chapter ends with a summary of three chapters on inheritance, reinforcing the cumulative nature of his argument.

Crossing, Absorption, and the Formation of New Races

Darwin turns to crossing in the third chapter, explaining that free intercrossing obliterates differences between allied breeds. When two breeds commingle in unequal numbers, the more numerous absorbs the other, a process influenced by prepotency, conditions of life, and natural selection. He notes that all organic beings occasionally intercross, with apparent exceptions being rare.

He then examines characters that seem incapable of fusion—chiefly those that have suddenly appeared in an individual—and discusses how crossing can modify old races or create new ones. Some crossed races, he observes, breed true from their first production. The chapter also addresses the crossing of distinct species in relation to domestic races, a topic that would later become central to debates about speciation.

The Accumulative Action of Changed Conditions

In the later excerpts, Darwin argues that the influence of changed conditions accumulates over generations. New flowers introduced to gardens do not vary at first, but after several years they begin to show variation. He cites the Dahlia, Zinnia, and Swan River daisy as examples where the timing of variation was recorded. The principle, he says, is that “the more a type has entered into a state of variation, the greater is its tendency to continue doing so.”

Darwin also discusses whether domestic productions could become so habituated to their conditions as to cease varying. He concludes that they never are exposed to uniform conditions long enough, and that even the most anciently cultivated plants and animals still vary. The chapter on accumulative action reinforces his broader argument that variation is not random but follows patterns that can be studied empirically.

Readers approaching this volume for the first time will benefit from tracking Darwin’s use of concrete examples—each named variety or experiment serves as a test of a general principle. The book is not a narrative but a series of linked arguments, and the chapter headings function as a roadmap. Pay attention to how Darwin qualifies his claims: he often admits when evidence is incomplete or when a conclusion is tentative. This caution is part of his scientific method, not a weakness.

Reading Darwin’s patient notes on pigeon reversion, I remembered my grandmother’s gnarled hands sorting seed packets, her quiet claim that flowers “remember” their wildness. My childhood copy of Texas Flowers in Natural Colors — Inside the Classic carried that same tenderness—each bloom a small argument for persistence, not perfection. Both books feel like watching someone breathe life back into a stubborn, familiar soil.