PIGEONS--continued.
ON THE ABORIGINAL PARENT-STOCK OF THE SEVERAL DOMESTIC RACES--HABITS OF
LIFE--WILD RACES OF THE ROCK-PIGEON--DOVECOTE-PIGEONS--PROOFS OF THE
DESCENT OF THE SEVERAL RACES FROM COLUMBA LIVIA--FERTILITY OF THE RACES
WHEN CROSSED--REVERSION TO THE PLUMAGE OF THE WILD ROCK-PIGEON--
CIRCUMSTANCES FAVOURABLE TO THE FORMATION OF THE RACES--ANTIQUITY AND
HISTORY OF THE PRINCIPAL RACES--MANNER OF THEIR FORMATION--SELECTION--
UNCONSCIOUS SELECTION--CARE TAKEN BY FANCIERS IN SELECTING THEIR BIRDS--
SLIGHTLY DIFFERENT STRAINS GRADUALLY CHANGE INTO WELL-MARKED BREEDS--
EXTINCTION OF INTERMEDIATE FORMS--CERTAIN BREEDS REMAIN PERMANENT, WHILST
OTHERS CHANGE--SUMMARY.