"Variation of Animals and Plants," Edition I., Volume II., page 431: "Did He cause the frame and mental qualities of the dog to vary in order that a breed might be formed of indomitable ferocity, with jaws fitted to pin down the bull for man's brutal sport ?"), with respect to variations not having been specially ordained.

Your metaphor of the river (203/4.

See Wallace, op.cit., pages 477-8.

He imagines an observer examining a great river-system, and finding everywhere adaptations which reveal the design of the Creator.

"He would see special adaptation to the wants of man in broad, quiet, navigable rivers, through fertile alluvial plains that would support a large population, while the rocky streams and mountain torrents were confined to those sterile regions suitable only for a small population of shepherds and herdsmen.') is new to me, and admirable; but your other metaphor, in which you compare classification and complex machines, does not seem to me quite appropriate, though I cannot point out what seems deficient.