Formation of Colonies by Lasius fuliginosus. 665 
In 1910 Crawley records that in 1898 he frequently 
saw workers which must have been wmbratus in a large 
colony of fuliginosus, and that they sometimes saluted 
each other when they met. Donisthorpe records that in 
1897 he found a large colony of /uliginosus in a hollow 
tree at Lymington, and that wmbratus was living with it, 
both species coming in and going out together. 
Wheeler, when describing an ant from Japan, which he 
considered might be the 6 female of /uliginosus, refers 
to the above records, and states that they clearly indicate 
that this method of colony foundation is actually adopted 
by fuliginosus queens in a manner analogous to that 
employed by the North American and European Formicae 
of the rufa, exsecta and microgyna groups when they enter 
nests of /. fusca and incerta. 
In 1911 Donisthorpe points out that fuliginosus often 
founds new colonies by branch nests as in the rufa group, 
which accounts for the fact that in a district where /ulz- 
ginosus occurs, so many colonies are often to be found. 
He states that the ? is unable to found her own colony, 
and that she enters a nest of wmbratus, and is accepted 
by them. He also mentions that on September 20th, 
1900, Mr. Tuck of Bury St. Edmunds sent him a worker 
of uwmbratus taken in a nest of fuliginosus in an old 
horse-chestnut stump in that neighbourhood. 
In Switzerland, in May 1905, Crawley observed workers 
from a colony of fuliginosus dragging dedlated females 
back into their nest after the marriage flight. He took 
a dozen of these 2, and isolated some and put others 
with $9 from their own nest; but none made any attempt 
to excavate cells or found colonies in any way, and in a 
few weeks all had died. 
On July Ist, 1910, we dug up a bagful of refuse from 
a large nest of L. fuliginosus in a hollow oak at Darenth 
Wood. It contained a number of 99, larvae, and a large 
number of ¢f and winged 29. This nest was divided 
into two portions, each containing an approximately equal 
number of ff and 22. During July most of the winged 
2, and all the fg, died or were killed by the $9, but 
about a dozen 2? were found with their wings removed. 
As some of these 22 subsequently laid a large quantity 
of eggs, it is highly probable that they had been fertilised 
in the nest by their brothers. Individuals selected from 
these dealated 2 2 were used in our experiments. 
