n garden-ant, one of the darkest skinned among our English
races, 'devotes itself principally to aphides which frequent twigs and
leaves'; especially, so far as I have myself observed, the bright green
aphis of the rose, and the closely allied little black aphis of the
broad bean. On the other hand a nearly related reddish ant pays
attention chiefly to those aphides which live on the bark of trees,
while the yellow meadow-ants, a far more subterranean species, keep
flocks and herds of the like-minded aphides which feed upon the roots of
herbs and grasses.

Sir John Lubbock, indeed, even suggests--and how the suggestion would
have charmed 'Civilisation' Buckle!--that to this difference of food and
habit the distinctive colours of the various species may very probably
be due. The ground which he adduces for this ingenious idea is a capital
example of the excellent use to which out-of-the-way evidence may be
cleverly put by a competent evolutionary thinker. 'The Baltic amber,' he
says, 'contains among the remains of many other insects a species of
ant intermediate between our small brown garden-ants and the little
yellow meadow-ants. This is possibly the stock from which these and
other allied species are descended. One is tempted to suggest that the
brown species which live so much in the open air, and climb up trees and
bushes, have retained and even deepened their dark colour; while others,
such as the yellow meadow-ant, which lives almost entirely below ground,
have become much paler.' He might have added, as confirmatory evidence,
the fact that the perfect winged males and females of the yellow
species, which fly about freely during the brief honeymoon in the open
air, are even darker in hue than the brown garden-ant. But how the light
colour of the neuter workers gets transmitted through these dusky
parents from one generation to another is part of that most insoluble
crux of all evolutionary reasoning--the transmission of special
qualities to neuters by parents who have never possessed them.

This last-mentioned yellow meadow-ant has carried the system of
domestication further in all probability than any other species among
its congeners. Not only do the yellow ants collect the root-feeding
aphides in their own nests, and tend them as carefully as their own
young, but they also gather and guard the eggs of the aphides, which,
till they come to maturity, are of course quite useless. Sir John
Lubbock found that his y