INTERRELATIONS OF INSECTS 341 
Though the diverse relations between myrmecophiles and ants 
are but partially understood, these aliens may for convenience 
be considered under five groups: captives, guests, visitors, im- 
truders and parasites. 
Captives.—Besides enslaving other species, as already men- 
tioned, ants make use of aphids and some coccids for the sake 
of their palatable products. The attendance of ants upon col- 
onies of plant lice is a common occurrence and one that repays 
careful observation. With the aid of a hand-lens, one may 
see the ants hastening about among the plant lice and patting 
them nervously with the antennz until at length some aphid 
responds by emitting from the end of the abdomen a glistening 
drop of watery fluid, which the ant snatches. This fluid, con- 
trary to prevalent accounts, is not furnished by the so-called 
honey-tubes of the aphid, but comes from the alimentary canal; 
the “ honey-tubes”’ are glandular indeed, but are probably 
repellent in function. In some instances ants give much care 
to their aphids, for example covering them with sheds of mud, 
which are reached through covered passageways. More than 
this, however, some ants actually collect aphid eggs and pre- 
serve them over winter as carefully as they do their own eggs. 
In one such instance, Lubbock found that the aphids upon 
hatching, after six months, were brought out by the ants and 
placed upon young shoots of the English daisy, their proper 
food plant. In our own country, as Forbes has discovered, 
the eggs of the corn root louse (Aphis maidiradicis) are col- 
lected in autumn by ants (especially of the genus Lasius) and 
stored in the underground nests. In winter, the eggs are taken 
to the deepest parts of the nest, and on bright spring days they 
are brought up and even scattered about temporarily in the 
sunshine; while if a nest is opened, the ants carry off the aphid 
eggs as they would their own. In spring, the ants tunnel to 
the roots of pigeon grass and smartweed, seize the aphids and 
carry them to these roots, and later to the roots of Indian 
corn. Throughout the year the ants exercise supervision over 
these aphids; occasionally, as Forbes says, an ant seizes a 
