Mi2 Psyche [December 
ready to hatch. Under two of the stones a couple of swhumbratus 
queens was found, each lurking quietly in a little cavity at the edge 
of a mass of cocoons nearly filling a large, shallow superficial cham- 
ber. 
2. A similar but even larger sitkaénsis nest, also under a pile of 
stones, under three of which subwmbratus queens were found. One 
of the queens was in a small cavity at the edge of a heap of co- 
cocns while each of the others was resting on the very center of a 
collection of cocoons nearly as large as my palm. ‘These queens 
had certainly been adopted and the picture presented was precisely 
like that of the recently adopted Formica consocians queens 
mounted on the cocoons and surrounded and fondled by the work- 
ers of F’. incerta (Wheeler 1906). When the nest was disturbed the 
queens hurried into the galleries and disappeared in the soil. 
They had evidently become strongly negatively heliotactic, unlike 
queens that are still running about on the soil immediately after 
the marriage flight. 
3. A fine sitkaénsis nest under a single large stone among the 
pines had an adopted subumbratus queen surrounded by dozens of 
workers in the center of a pile of worker and female cocoons nearly 
as large as my hand. She quickly slipped into a burrow and was 
only recovered by digging down into the soil to a depth of more than 
six inches. In this nest a few of the female sitkaénsis pupe were 
naked, 7. e., not enclosed in cocoons. 
Further search in the same locality brought to ight two mixed 
colonies consisting of swbumbratus and sitkaénsis workers. I failed 
to find the queens of the former species, which were probably pres- 
ent but hiding deep in the soil. The failure to find them is not 
surprising as one very rarely secures the mother queen of a fully 
developed colony of any of our species of Lasius without extensive 
and very careful excavation of the nest. 
The foregoing observations show that the swbwmbratus queen has 
to acquire the brood odor of the host before she can be accepted. 
She therefore lurks very near the cocoons in a small earthen cavity 
and somewhat later, in the early stage of adoption, like Formica 
consocians, takes up a position on the brood. This renders her 
immune to attack by the host workers and gradually accustoms 
them to her presence. That adoption can be secured in very 
populous and flourishing colonies of sitkaénsis is shown by the 
