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case had come under his notice of a variation in the form of a human
member； in the person of a Maltese； of the name of Gratio Kelleia； who
was born with six fingers upon each hand； and the like number of toes
to each of his feet。 That was a case of spontaneous variation。 Nobody
knows why he was born with that number of fingers and toes； and as we
don't know； we call it a case of 〃spontaneous〃 variation。 There is
another remarkable case also。 I select these； because they happen to
have been observed and noted very carefully at the time。 It frequently
happens that a variation occurs； but the persons who notice it do not
take any care in noting down the particulars； until at length； when
inquiries come to be made； the exact circumstances are forgotten； and
hence； multitudinous as may be such 〃spontaneous〃 variations； it is
exceedingly difficult to get at the origin of them。
The second case is one of which you may find the whole details in the
〃Philosophical Transactions〃 for the year 1813； in a paper communicated
by Colonel Humphrey to the President of the Royal Society；〃On a new
Variety in the Breed of Sheep；〃 giving an account of a very remarkable
breed of sheep； which at one time was well known in the northern states
of America； and which went by the name of the Ancon or the Otter breed
of sheep。 In the year 1791； there was a farmer of the name of Seth
Wright in Massachusetts； who had a flock of sheep； consisting of a ram
and； I think； of some twelve or thirteen ewes。 Of this flock of ewes；
one at the breeding…time bore a lamb which was very singularly formed；
it had a very long body； very short legs； and those legs were bowed！ I
will tell you by…and…by how this singular variation in the breed of
sheep came to be noted； and to have the prominence that it now has。 For
the present； I mention only these two cases； but the extent of variation
in the breed of animals is perfectly obvious to any one who has studied
natural history with ordinary attention； or to any person who compares
animals with others of the same kind。 It is strictly true that there
are never any two specimens which are exactly alike； however similar；
they will always differ in some certain particular。
Now let us go back to Atavism；to the hereditary tendency I spoke of。
What will come of a variation when you breed from it； when Atavism
comes； if I may say so； to intersect variation？ The two cases of which
I have mentioned the history； give a most excellent illustration of
what occurs。 Gratio Kelleia； the Maltese； married when he was
twenty…two years of age； and； as I suppose there were no six…fingered
ladies in Malta； he married an ordinary five…fingered person。 The
result of that marriage was four children； the first； who was christened
Salvator； had six fingers and six toes； like his father； the second was
George； who had five fingers and toes； but one of them was deformed；
showing a tendency to variation； the third was Andre； he had five
fingers and five toes； quite perfect； the fourth was a girl； Marie； she
had five fingers and five toes； but her thumbs were deformed； showing a
tendency toward the sixth。
These children grew up； and when they came to adult years； they all
married； and of course it happened that they all married five…fingered
and five…toed persons。 Now let us see what were the results。 Salvator
had four children； they were two boys； a girl； and another boy； the
first two boys and the girl were six…fingered and six…toed like their
grandfather； the fourth boy had only five fingers and five toes。 George
had only four children； there were two girls with six fingers and six
toes； there was one girl with six fingers and five toes on the right
side； and five fingers and five toes on the left side； so that she was
half and half。 The last； a boy； had five fingers and five toes。 The
third； Andre； you will recollect； was perfectly well…formed； and he had
many children whose hands and feet were all regularly developed。 Marie；
the last； who； of course； married a man who had only five fingers； had
four children； the first； a boy； was born with six toes； but the other
three were normal。
Now observe what very extraordinary phenomena are presented here。 You
have an accidental variation arising from what you may call a
monstrosity； you have that monstrosity tendency or variation diluted in
the first instance by an admixture with a female of normal construction；
and you would naturally expect that； in the results of such an union；
the monstrosity； if repeated； would be in equal proportion with the
normal type； that is to say； that the children would be half and half；
some taking the peculiarity of the father； and the others being of the
purely normal type of the mother； but you see we have a great
preponderance of the abnormal type。 Well； this comes to be mixed once
more with the pure； the normal type； and the abnormal is again produced
in large proportion； notwithstanding the second dilution。 Now what
would have happened if these abnormal types had intermarried with each
other； that is to say； suppose the two boys of Salvator had taken it
into their heads to marry their first cousins； the two first girls of
George； their uncle？ You will remember that these are all of the
abnormal type of their grandfather。 The result would probably have
been； that their offspring would have been in every case a further
development of that abnormal type。 You see it is only in the fourth；
in the person of Marie； that the tendency； when it appears but slightly
in the second generation； is washed out in the third； while the progeny
of Andre； who escaped in the first instance； escape altogether。
We have in this case a good example of nature's tendency to the
perpetuation of a variation。 Here it is certainly a variation which
carried with it no use or benefit； and yet you see the tendency to
perpetuation may be so strong； that； notwithstanding a great admixture
of pure blood； the variety continues itself up to the third generation；
which is largely marked with it。 In this case； as I have said； there
was no means of the second generation intermarrying with any but
five…fingered persons； and the question naturally suggests itself； What
would have been the result of such marriage？ Reaumur narrates this
case only as far as the third generation。 Certainly it would have been
an exceedingly curious thing if we could have traced this matter any
further； had the cousins intermarried； a six…fingered variety of the
human race might have been set up。
To show you that this supposition is by no means an unreasonable one；
let me now point out what took place in the case of Seth Wright's
sheep； where it happened to be a matter of moment to him to obtain a
breed or raise a flock of sheep like that accidental variety that I
have describedand I will tell you why。 In that part of Massachusetts
where Seth Wright was living； the fields were separated by fences； and
the sheep； which were very active and robust； would roam abroad； and
without much difficulty jump over these fences into other people's
farms。 As a matter of course； this exuberant activity on the part of
the sheep constantly gave rise to all sorts of quarrels； bickerings；
and contentions among the farmers of the neighbourhood； so it occurred
to Seth Wright； who was； like his successors； more or less 'cute； that
if he could get a stock of sheep like those with the bandy legs； they
would not be able to jump over the fences so readily； and he acted upon
that idea。 He killed his old ram； and as soon as the young one arrived
at maturity； he bred altogether from it。 The result was even more
striking than in the human experiment which I mentioned just now。
Colonel Humphreys testifies that it always happened that the offspring
were either pure Ancons or pure ordinary sheep； that in no case was
there any mixing of the Ancons with the others。 In consequence of
this； in the course of a very few years； the farmer was able to get a
very considerable flock of this variety； and a large number of them
were spread throughout Massachusetts。 Most unfortunately； howeverI
suppose it was because they were so commonnobody took enough notice
of them to preserve their skeletons； and although Colonel Humphreys
states that he sent a skeleton to the President of the Royal Society at
the same time that he forwarded his paper； I am afraid that the variety
has entirely disappeared； for a short time after these sheep had become
prevalent in that district； the Merino sheep were introduced； and as
their wool was much more valuable； and as they were a quiet race of
sheep； and showed no tendency to trespass or jump over fences； the
Otter breed of sheep； the wool of which was inferior to that of the
Merino； was gradually allowed to die out。
You see that these facts illustrate perfectly well what may be done if
you take care to breed from stocks that are similar to each other。
After having got a variation； if； by crossing a variation with the
original stock； you multiply that variation； and then take care to keep
that variation distinct from the original stock； and make them breed
together；then you may almost certainly