birds the legs had become from any cause reduced in weight,
this would give the false appearance of the wings having increased in
relative weight. Now a reduction of this nature has certainly occurred
with the Burmese Jumper, in which the legs are abnormally short, and in
the two Hamburghs and Silk fowl, the legs, though not short, are formed
of remarkably thin and light bones. I make these statements, not
judging by mere eyesight, but after having calculated the weights of
the leg-bones relatively to those of _G. bankiva_, according to the
only two standards of comparison which I could use, namely, the
relative lengths of the head and sternum; for I do not know the weight
of the body in _G. bankiva_, which would have been a better standard.
According to these standards, the leg-bones in these four fowls are in
a marked manner far lighter than in any other breed. It may therefore
be concluded that in all cases in which the legs have not been through
some unknown cause much reduced in weight, the wing-bones have become
reduced in weight relatively to the leg-bones, in comparison with those
of _G. bankiva_. And this reduction of weight may, I apprehend, safely
be attributed to disuse.

To make the foregoing table quite satisfactory, it ought to have been
shown that in the eight first birds the leg-bones have not actually
increased in weight out of due proportion with the rest of the body;
this I cannot show, from not knowing, as already remarked, the weight
of the wild Bankiva.[434] I am indeed inclined to suspect that the
leg-bones in the Dorking, No. 2 in the table, are proportionally too
heavy; but this bird was a very large one, weighing 7 lb. 2 oz., though
very thin. Its leg-bones were more than ten times as heavy as those of
the Burmese Jumper! I tried to ascertain the length both of the
leg-bones and wing-bones relatively to other parts of the body and
skeleton; but the whole organisation in these birds, which have been so
long domesticated, has become so variable, that no certain conclusions
could be reached. For instance, the legs of the above Dorking cock were
nearly three-quarters of an inch too short relatively to the length of
the sternum, and more than {273} three-quarters of an inch too long
relatively to the length of the skull, in comparison with these same
parts in _G. ban