e number of domesticated rabbits
of nearly the same size with the wild rabbit, it would have been a
simple task to have measured and compared the capacities of their
skulls. But this is not the case; almost all the domestic breeds have
larger bodies than wild rabbits, and the lop-eared kinds are more than
double their weight. As a small animal has to exert its senses,
intellect, and instincts equally with a large animal, we ought not by
any means to expect an animal twice or thrice as large as another to
have a brain of double or treble the size.[273] Now, after weighing
{125} the bodies of four wild rabbits, and of four large but not
fattened lop-eared rabbits, I find that on an average the wild are to
the lop-eared in weight as 1 to 2.47; in average length of body as 1 to
1.41; whilst in capacity of skull (measured as hereafter to be
described) they are only as 1 to 1.15. Hence we see that the capacity
of the skull, and consequently the size of the brain, has increased but
little, relatively to the increased size of the body; and this fact
explains the narrowness of the skull relatively to its length in all
domestic rabbits.

In the upper half of the following table I have given the measurements
of the skulls of ten wild rabbits; and in the lower half of eleven
thoroughly domesticated kinds. As these rabbits differ so greatly in
size, it is necessary to have some standard by which to compare the
capacities of their skulls. I have selected the length of skull as the
best standard, for in the larger rabbits it has not, as already stated,
increased in length so much as the body; but as the skull, like every
other part, varies in length, neither it nor any other part affords a
perfect standard.

In the first column of figures the extreme length of the skull is given
in inches and decimals. I am aware that these measurements pretend to
greater accuracy than is possible; but I have found it the least
trouble to record the exact length which the compass gave. The second
and third columns give the length and weight of body, whenever these
measurements have been made. The fourth column gives the capacity of
the skull by the weight of small shot with which the skulls had been
filled; but it is not pretended that these weights are accurate within
a few grains. In the fifth column the capacit