THE VARIATION OF ANIMALS AND PLANTS UNDER DOMESTICATION.

VOLUME II.

CHAPTER 2.XIII.

INHERITANCE continued--REVERSION OR ATAVISM.

DIFFERENT FORMS OF REVERSION.
IN PURE OR UNCROSSED BREEDS, AS IN PIGEONS, FOWLS, HORNLESS CATTLE AND SHEEP, IN CULTIVATED PLANTS.
REVERSION IN FERAL ANIMALS AND PLANTS.
REVERSION IN CROSSED VARIETIES AND SPECIES.
REVERSION THROUGH BUD-PROPAGATION, AND BY SEGMENTS IN THE SAME FLOWER OR FRUIT.
IN DIFFERENT PARTS OF THE BODY IN THE SAME ANIMAL.
THE ACT OF CROSSING A DIRECT CAUSE OF REVERSION, VARIOUS CASES OF, WITH INSTINCTS.
OTHER PROXIMATE CAUSES OF REVERSION.
LATENT CHARACTERS.
SECONDARY SEXUAL CHARACTERS.
UNEQUAL DEVELOPMENT OF THE TWO SIDES OF THE BODY.
APPEARANCE WITH ADVANCING AGE OF CHARACTERS DERIVED FROM A CROSS.
THE GERM, WITH ALL ITS LATENT CHARACTERS, A WONDERFUL OBJECT.
MONSTROSITIES.
PELORIC FLOWERS DUE IN SOME CASES TO REVERSION.

The great principle of inheritance to be discussed in this chapter has been recognised by agriculturists and authors of various nations, as shown by the scientific term ATAVISM, derived from atavus, an ancestor; by the English terms of REVERSION, or THROWING-BACK; by the French PAS-EN-ARRIERE; and by the German RUCKSCHLAG, or RUCKSCHRITT. When the child resembles either grandparent more closely than its immediate parents, our attention is not much arrested, though in truth the fact is highly remarkable; but when the child resembles some remote ancestor or some distant member in a collateral line,--and in the last case we must attribute this to the descent of all the members from a common progenitor,--we feel a just degree of astonishment. When one parent alone displays some newly-acquired and generally inheritable character, and the offspring do not inherit it, the cause may lie in the other parent having the power of prepotent transmission. But when both parents are similarly characterised, and the child does not, whatever the cause may be, inherit the character in question, but resembles its grandparents, we have one of the simplest cases of reversion. We continually see another and even more simple case of atavism, though not generally included under this head, namely, when the son more closely resembles his maternal than his paternal grand-sire in some male attribute, as in any peculiarity in the beard of man, the horns of the bull, the hackles or comb of the cock, or, as in certain diseases necessarily confined to the male sex; for as the mother cannot possess or exhibit such male attributes, the child must inherit them, through her blood, from his maternal grandsire.

The Variation of Animals and Plants Under Domestication V2 Page 06

19th Century English Literature

Charles Darwin

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Charles Darwin

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