1927] Occurrence of the Pavement Ant in Boston 165 
a crevice in the floor near their nest which was situated in the 
outer masonry of the building. A number of workers were still 
running about the crevice from which they had permitted their 
voluminous sexual forms to escape. The apartment building 
surrounds a court containing a garden. Probably the ants had 
lived in the soil of this enclosure till the advent of cold weather 
and had then migrated into the vestibule. At any rate they were 
here able to bring their sexual forms to maturity and to stage 
their nuptial flight at a most unusual season, for the normal 
marriage flight, according to European observers, occurs in July, 
or at least sometime between June and September. Since the 
apartment building is very near the Charles River it will be in- 
teresting to determine whether the ants may not be spreading 
from the parked esplanade which borders the river in that part 
of the city. 
