examined three) of half-lops (see figure 5), in which one ear stands
upright, and the other and longer ear hangs down; for in these skulls there
was a plain difference in the form and direction of the bony meatus on the
two sides. But it is a much more interesting fact, that the changed
direction and increased size of the bony meatus have slightly affected on
the same side the structure of the whole skull. I here give a drawing
(figure 11) of the skull of a half-lop; and it may be observed that the
suture between the parietal and frontal bones does not run strictly at
right angles to the longitudinal axis of the skull; the left frontal bone
projects beyond the right one; both the posterior and anterior margins of
the left zygomatic arch on the side of the lopping ear stand a little in
advance of the corresponding bones on the opposite side. Even the lower jaw
is affected, and the condyles are not quite symmetrical, that on the left
standing a little in advance of that on the right. This seems to me a
remarkable case of correlation of growth. Who would have surmised that by
keeping an animal during many generations under confinement, and so leading
to the disuse of the muscles of the ears, and by continually selecting
individuals with the longest and largest ears, he would thus indirectly
have affected almost every suture in the skull and the form of the lower
jaw!

In the large lop-eared rabbits the only difference in the lower jaw, in
comparison with that of the wild rabbit, is that the posterior margin of
the ascending ramus is broader and more inflected. The teeth in neither jaw
present any difference, except that the small incisors, beneath the large
ones, are proportionately a little longer. The molar teeth have increased
in size proportionately with the increased width of the skull, measured
across the zygomatic arch, and not proportionally with its increased
length. The inner line of the sockets of the molar teeth in the upper jaw
of the wild rabbit forms a perfectly straight line; but in some of the