final causes leads their pursuers a long way; but even those hardy
teleologists, who are ready to break through all the laws of physics in
chase of their favourite will-o'-the-wisp, may be puzzled to discover
what purpose could be attained by the stunted legs of Seth Wright's ram
or the hexadactyle members of Gratio Kelleia.

Varieties then arise we know not why; and it is more than probable that
the majority of varieties have arisen in this "spontaneous" manner,
though we are, of course, far from denying that they may be traced, in
some cases, to distinct external influences; which are assuredly
competent to alter the character of the tegumentary covering, to change
colour, to increase or diminish the size of muscles, to modify
constitution, and, among plants, to give rise to the metamorphosis of
stamens into petals, and so forth. But however they may have arisen,
what especially interests us at present is, to remark that, once in
existence, varieties obey the fundamental law of reproduction that like
tends to produce like; and their offspring exemplify it by tending to
exhibit the same deviation from the parental stock as themselves.
Indeed, there seems to be, in many instances, a pre-potent influence
about a newly-arisen variety which gives it what one may call an unfair
advantage over the normal descendants from the same stock. This is
strikingly exemplified by the case of Gratio Kelleia, who married a
woman with the ordinary pentadactyle extremities, and had by her four
children, Salvator, George, Andre, and Marie. Of these children
Salvator, the eldest boy, had six fingers and six toes, like his
father; the second and third, also boys, had five fingers and five toes,
like their mother, though the hands and feet of George were slightly
deformed. The last, a girl, had five fingers and five toes, but the
thumbs were slightly deformed. The variety thus reproduced itself
purely in the eldest, while the normal type reproduced itself purely in