368 Trans. Acad. Sci. of St. Louis 
silver-winged flies noticeable at this time; they confined 
their attention and movements to the spot directly in 
front of the burrow in the wood, although none was ac- 
tually seen to enter the hole. 
These wasps have learned to use sites other than 
carpenter-bee burrows in wood. In a clay bank at 
Chesterfield, Mo., on July 3, 1921, I found where two of 
them had used the old burrows of Entechnia taurea. In 
the clay bank at Wickes also a burrow of A. abrupta 
was found containing the characteristic nest and grass 
stuffing of this wasp. 
The life history of this creature is not half told, and 
the road to the discovery of more details is beset with 
many difficulties. Even if, after weeks of watching, one 
does find a nest, one soon grows tired of only seeing the 
wasp enter and leave; all of her wonderful work is done 
in the dark and behind closed doors. Furthermore, the 
attitude of this owner of the burrow toward our prowl- 
ing and meddling about her home is not in the least 
friendly, while the attitude of that larger owner of the 
premises involved is often precisely the same, in an 
intensified degree, and frequently expressed in as sting- 
ing a reproof as the other. To be sure, one can await 
the absence of proprietors, both large and small, and 
with an ax deface some stranger’s house or shed and 
thus add something to the biology of the creature, but 
the opening up of the nest can at best add but little to 
the solving of the problems of behavior—the exhibitions 
of habit, instinct, intelligence, ete., which one can often 
observe in creatures that work in the open. 
