s, are known, but the origin of very few has been
accurately recorded, and of these we will select two as more especially
illustrative of the main features of variation. The first of them is
that of the "Ancon," or "Otter" sheep, of which a careful account is
given by Colonel David Humphreys, F.R.S., in a letter to Sir Joseph
Banks, published in the Philosophical Transactions for 1813. It appears
that one Seth Wright, the proprietor of a farm on the banks of the
Charles River, in Massachusetts, possessed a flock of fifteen ewes and
a ram of the ordinary kind. In the year 1791, one of the ewes presented
her owner with a male lamb, differing, for no assignable reason, from
its parents by a proportionally long body and short bandy legs, whence
it was unable to emulate its relatives in those sportive leaps over the
neighbours' fences, in which they were in the habit of indulging, much
to the good farmer's vexation.

The second case is that detailed by a no less unexceptionable authority
than Reaumur, in his 'Art de faire eclore les Poulets'. A Maltese
couple, named Kelleia, whose hands and feet were constructed upon the
ordinary human model, had born to them a son, Gratio, who possessed six
perfectly movable fingers on each hand, and six toes, not quite so well
formed, on each foot. No cause could be assigned for the appearance of
this unusual variety of the human species.

Two circumstances are well worthy of remark in both these cases. In
each, the variety appears to have arisen in full force, and, as it were,
per saltum; a wide and definite difference appearing, at once, between
the Ancon ram and the ordinary sheep; between the six-fingered and
six-toed Gratio Kelleia and ordinary men. In neither case is it possible
to point out any obvious reason for the appearance of the variety.
Doubtless there were determining causes for these as for all other
phenomena; but they do not appear, and we can be tolerably certain that
what are ordinarily understood as changes in physical conditions, as in
climate, in food, or the like, did not take place and had nothing to do
with the matter. It was no case of what is commonly called adaptation
to circumstances; but, to use a conveniently erroneous phrase, the
variations arose spontaneously. The fruitless search after 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'