96 
former inhabitant, neatly enlarged and rounded off so that it has 
the appearance of an unused cell. The bits of mud bitten off in 
this work are not cast aside, but plastered on the cell’s walls, 
where they will come in handy for recapping the cell after another 
spider is stored in it. It is probable that the wasps use any cell 
in the nest they find vacant and do not concern themselves about 
its builder. 
The operations as related above are frequently rendered more 
complex or irregular through the erratic behavior of one or more 
of the female wasps. Thus it often happens that when a spider 
has been tucked away in a cell, not one, but two or three wasps 
give it their attention, so that we can only guess which is the 
lawful owner of the prize. The wasps will crowd about the 
cell; one will poke in her head and become interested in the 
spider, then she will withdraw and a second Paragenia now steps 
forward and investigates likewise. Perhaps they feed on the 
spider’s mouth or leg juices. On one occasion a wasp hauled 
the spider out of the ‘cell and let it fall to the bottom of 
the node, much to the consternation of the others. Again, late 
in the afternoon a Paragenia brought in a spider from the field, 
but there was no cell ready to store it in. Nothing daunted, 
however, the wasp, after wandering about a little, dropped her 
burden on the internode and set to work to make a cell, building 
it up from a mere rudiment—two short strips of mud_ laid 
down many hours previously. She worked rapidly, nevertheless 
darkness put an end to her industry. 1 watched her plastering 
away until 6:10 p. m., and after supper visited the nest again at 
7:50 p. m. to find the cell incomplete, the spider unstored, and 
three female Paragenia about the cell-mass. Thus it 1s evident 
that the females, at least in part, stand by their nest during the 
night. At 7 o’clock the next morning the spider still lay in last 
night’s position, but by 8:45 a. m. had been stored in an old cell 
whose newly-made emergence hole had been enlarged. I pulled 
the spider out of this cell, and the alert wasp, after cutting off 
the remaining leg, once more stored it within. Sometimes a couple 
of wasps will simultaneously build cells side by side—close quar- 
ters indeed for such long-legged sprawling creatures—and though 
they may necessarily interfere with each other’s work, there is no 
quarreling. Again, capped cells may for no obvious reason be 
opened and sealed up again. One such cell contained a Paragenia 
cocoon, another a spider five days old. In another case one wasp 
was plastering up a cell which contained a spider while a second 
wasp was plastering as well as biting open this same cell. But 
when the egg (here perhaps not the first one) was deposited, the 
cell was closed without interference. 

