The Descent of Man

kingdom. (1. Isidore Geoffroy St.-Hilaire gives
a detailed account of the position assigned to
man by various naturalists in their classifications:
'Hist. Nat. Gen.' tom. ii. 1859, pp. 170-
189.) Spiritual powers cannot be compared or
classed by the naturalist: but he may endeavour
to shew, as I have done, that the mental faculties
of man and the lower animals do not differ
in kind, although immensely in degree. A difference
in degree, however great, does not justify
us in placing man in a distinct kingdom, as will
perhaps be best illustrated by comparing the
mental powers of two insects, namely, a coccus
or scale-insect and an ant, which undoubtedly
belong to the same class. The difference is here
greater than, though of a somewhat different
kind from, that between man and the highest
mammal. The female coccus, whilst young,
attaches itself by its proboscis to a plant; sucks
the sap, but never moves again; is fertilised and
lays eggs; and this is its whole history. On the
other hand, to describe the habits and mental