94 
third the circumference of the bamboo was separated by a large 
crack from the main body for about two-thirds the length of the 
stump. The elastic slab was on the overhanging side and could 
be further drawn away, thus more fully exposing the contents 
of two and a half nodes. The topmost of these was soon des- 
tined to contain a single cell of an old Macromeris wasp, the 
second sheltered the mud cells of Paragenia, while a portion of 
the node near the base appeared to furnish a nest for Diacamma, 
one of the large ponerine ants. 
On July 10, 1917, this Paragenia nest was composed of eight 
mud cells, all sealed and vertically arranged, one touching the 
other, in one side of the node; on August ‘16 there were twenty- 
two sealed cells, one unsealed, and the rudiment of a twenty- 
fourth. The nest was examined almost daily up to September 
12, or for more than two months. It is probable that on July 10 
this nest was already two or three weeks old. The greatest 
number of wasps present at one time in or about it was eight. 
It is probable that in most cases but one wasp begins the con- 
struction of the nest. The cells (Fig. 43) are longer and broader 
than high, and their point of attachment forms the basal side. 
They are composed entirely of mud collected in some moist spot. 
This mud, gathered by the jaws of the wasp, is turned over and 
over in her mouth-parts until it assumes the right consistency, 
when, lowering her head and at the same time bending the abdo- 
men forward beneath her until its dorsal tip pierces the ball of 
mud, now almost touching the bamboo, she applies part of the 
mud to the wood, where it is spread on as desired with dorsal 
end of the abdomen. This mason work is repeated until the 
mouthful of mud is expended, when the architect flies away again 
to renew the supply. The walls of the cells rise evenly, and since 
the builder apples and plasters on the mud from the inside, the 
structure is always smoother within, and the wasp often assumes 
a very cramped position as she works in the nearly completed 
cell. The length of time occupied in building such a cell is 
variable, as the work is frequently done intermittently, but often 
extends beyond a day. When the cell is ready for the reception 
of a spider it has a large well-rounded orifice. 
I did not see any of these insects capture their prey (/Hetero- 
poda gemella Linn.). Paragenia, though alert, has by reason of 
its very long legs a draggling or drooping sort of gait as she 
searches about the trash at the base of bamboo clumps and other 
likely places for suitable spiders. These are more or less de- 
legged in the field; perhaps all but the short anterior pair of 
legs (pedipalps) are severed from the body, or one or more of 
the true legs may remain attached. The wasp grasps her prey 
