The Descent of Man

animal as by an old one. The following case,
however, can hardly be so considered: a trustworthy
naturalist, Mr. Gardner (14. 'Travels in
the Interior of Brazil,' 1846, p. 111. I have given,
in my 'Journal of Researches,' p. 463, an account
of the habits of the Birgus.), whilst watching a
shore-crab (Gelasimus) making its burrow,
threw some shells towards the hole. One rolled
in, and three other shells remained within a few
inches of the mouth. In about five minutes the
crab brought out the shell which had fallen in,
and carried it away to a distance of a foot; it
then saw the three other shells lying near, and
evidently thinking that they might likewise roll
in, carried them to the spot where it had laid
the first. It would, I think, be difficult to distinguish
this act from one performed by man by
the aid of reason.
Mr. Bate does not know of any well-marked
case of difference of colour in the two sexes of
our British crustaceans, in which respect the