67 
_ n practice probably to be understood as a means of hastening 
theii hatching I h'ave repeatedly seen these ants m confine¬ 
ment with a little mass of aphis eggs, turn the eggs about one 
by one with their mandibles, licking each carefully at the same 
time as if to clean the surface. These anxious caies aie of co 
explained by the use the ants make of the root lice, whose ex¬ 
creted fluids they lap up greedily as soon as the young lice 
begin to feed. They are not, however, wholly dependent on this 
food supply, at least in early spring, as I have ‘ h em kih 
and drag away at that season soft-bodied insect laivse, dou it 
less to suck their juices out as food. Th s has been a somewhat 
rare occurrence, however, and has rarely been no ice y 
among ants which had plant lice in their possession. Once, 
however, ants of this species occurring abundantly in corn he s 
were observed September 22 to carry bits of dead insects into 
their burrows, together with a living corn root louse. 
That the young of the first generation are helped by the ants 
to a favorable position on the roots of the plants they infest* 
quite beyond question. It is shown (1) by the fact that m many 
cases the aphis could not get access to such roots unless these 
had been previously laid bare by the tunneling of the ants, 
and (2) by the behavior of ants with mines already constructed, 
when the root aphis is offered to them. We have’ repeated y 
performed the experiment of starting colonies of ants on hi Is 
of corn in the insectary and exposing root lice fr°m the fie d 
to their attentions, and in every such instance, J 
was well established, the helpless insects have been seized by the 
ants, often almost instantly, and conveyed undei gro > 
we would later find them feeding and breeding on the* roots ° 
the corn. In many cases in the field, we have found the young 
root aphis or. sprouting weeds (especially pigeon-grass), wine 
have been sought out by the ants before the leaves had1 shown 
above the ground; and, similarly, when the field is panted1 to 
corn, these ardent explorers will frequently discover the sp 
ing kernel in the earth, and mine along the starting stem a 
place the plant lice upon it. 
We have also abundant evidence that ants excavate hi Is 
of corn in verv early spring, when they have as yet neither 
eggs nor plant lice in their possession, and some days be¬ 
fore the possible appearance of the second or 
ation. I can only account for this practice on the supposi¬ 
tion that these ants expect later to obtain eggs or >o » 
with which to stock their burrows, made ready m advance. 
Certainly this is true with respect to the second £“ n a l ®" 
the root aphis. When winged lice of this brood h^'i' to aPPear 
it is a common thing to find the small brown ant scattenng far 
and wide over fields not previously in corn, and containing co - 
sequentlv no plant lice in any stage, burrowing - 
of corn, and carrying underground such corn root ^ c ® “ 
within their range. Cor example, a corn field on sodnieai 1 
Ill., was searched May 18 of a backward spring, aftei a penod 
