SELECTION--_continued._
NATURAL SELECTION AS AFFECTING DOMESTIC PRODUCTIONS--CHARACTERS WHICH
APPEAR OF TRIFLING VALUE OFTEN OF REAL IMPORTANCE--CIRCUMSTANCES FAVOURABLE
TO SELECTION BY MAN--FACILITY IN PREVENTING CROSSES, AND THE NATURE OF THE
CONDITIONS--CLOSE ATTENTION AND PERSEVERANCE INDISPENSABLE--THE PRODUCTION
OF A LARGE NUMBER OF INDIVIDUALS ESPECIALLY FAVOURABLE--WHEN NO SELECTION
IS APPLIED, DISTINCT RACES ARE NOT FORMED--HIGHLY-BRED ANIMALS LIABLE TO
DEGENERATION--TENDENCY IN MAN TO CARRY THE SELECTION OF EACH CHARACTER TO
AN EXTREME POINT, LEADING TO DIVERGENCE OF CHARACTER, RARELY TO
CONVERGENCE--CHARACTERS CONTINUING TO VARY IN THE SAME DIRECTION IN WHICH
THEY HAVE ALREADY VARIED--DIVERGENCE OF CHARACTER, WITH THE EXTINCTION OF
INTERMEDIATE VARIETIES, LEADS TO DISTINCTNESS IN OUR DOMESTIC RACES--LIMIT
TO THE POWER OF SELECTION--LAPSE OF TIME IMPORTANT--MANNER IN WHICH
DOMESTIC RACES HAVE ORIGINATED--SUMMARY ... Page 224