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their habitation. About two inches from this collection of eggs a 
smartweed root had been exposed by the ants under ground, and on 
this about fifteen of the root-lice were feeding. 
In another nest explored on the same day the burrows were 
from one tenth to one eighth of an inch in diameter. Under a space 
of two square feet four clusters of root-louse eggs and some recently 
hatched aphids were found. Six young aphids on the roots of a 
smartweed in one of these burrows were promptly seized by the ants 
and carried farther into their retreat. At four o'clock p. m. most of 
the ants had retired for the day, but two brought out an aphis each, 
taking it back, however, in less than two minutes. Twenty-two 
ants were found in this nest, together with a bunch of aphis eggs 
about as large as a pea. Two inches from this mass of eggs was a 
sprouting smartweed that had not yet broken ground, and on it were 
a number of young root-lice. When exposed by digging, the ants 
immediately seized them and carried them away. Roots of smart- 
weed, grasses, and ragweed exposed in burrows, sometimes had no 
root-lice on them, although in one case a root-louse was found on a 
ragweed root. 
May 5 ten nearly grown aphids were taken from a smartweed 
root and placed on the bare ground. They crawled actively about 
and two of them entered a crack in the earth as if to escape the light. 
One of these was found by an ant which carried it away. Two small 
ones crawled about four feet and stopped as if exhausted, but two 
larger aphids traveled more than ten feet in an hour and twenty min- 
utes. All these aphids were seemingly averse to the light, and 
crawled away from the sun. 
May 8 several young of the second brood were found. Three 
full-grown stem-mothers were unearthed, near one of which were 
four young, and near another, two. The third was in the act of 
giving birth to an aphis, of which an ant took possession as soon as 
it was born and carried it to a new plant. Presently all the other 
young were carried away by ants and placed on plant roots. A 
second aphis was born from the same mother within forty minutes 
after the first. This also was soon carried away and placed on a 
fresh plant. 
On the 9th, which was cool and damp, a heavy rain having fallen 
during the morning, the ants were seen taking the root-lice from the 
old smartweed roots — which were now dead and dry or even de- 
cayed — and placing them on the roots of younger plants. 
On May 12 Mr. Kelly took a corn root-aphis from a plant and 
placed it on the ground. A root-louse ant {Lasius alienus) found it 
presently, carried it away to a distance of four feet, placed it on the 
