The Descent of Man

slaves. They move the eggs of their aphides, as
well as their own eggs and cocoons, into warm
parts of the nest, in order that they may be
quickly hatched; and endless similar facts could
be given. (2. Some of the most interesting facts
ever published on the habits of ants are given
by Mr. Belt, in his 'Naturalist in Nicaragua,'
1874. See also Mr. Moggridge's admirable
work, 'Harvesting Ants,' etc., 1873, also 'L'Instinct
chez les Insectes,' by M. George Pouchet,
'Revue des Deux Mondes,' Feb. 1870, p. 682.)
On the whole, the difference in mental power
between an ant and a coccus is immense; yet no
one has ever dreamed of placing these insects
in distinct classes, much less in distinct kingdoms.
No doubt the difference is bridged over
by other insects; and this is not the case with
man and the higher apes. But we have every
reason to believe that the breaks in the series
are simply the results of many forms having
become extinct.