ZeObpstkR VATIONS: ON: PSITAYRUS 252 
to be to chase certain workers, probably those that 
desired to lay eggs. When she caught a worker 
she clasped it to the underside of her abdomen and 
rolled over with it, apparently endeavouring to 
squeeze or sting it. But the worker was too small 
to get hurt, and soon slipped away. The incurva- 
ture of the abdomen, and the ridges under its tip, 
peculiar to all Pszthyrus queens, must be of great 
assistance in thus dealing with refractory workers, 
and this, I think, is probably their function. 
On July 24, at 6.0 p.m., she had laid a batch of 
eggs in a cell which must have been constructed 
very rapidly, because there was no sign of it at 5.0. 
She guarded the cell from the attacks of the workers 
in much the same manner as a /apidarius queen, 
but I noticed she spent a much longer time in giving 
the finishing touches to the cell, and while she was 
doing this the workers dared not approach. 
At 9.30 p.m. she was still guarding the cell from 
the workers, several of which had now grown very 
bold, and occasionally succeeded in biting holes in 
it, the Pszthyrus having become less vigilant. The 
workers shook and revolved their wings in the 
greatest excitement while they were attacking the 
cell. She carefully sealed up every rent they made. 
Next morning (July 25) the cell still stood, and 
the workers had ceased to assault it. 
At 8.0 p.m. the foundation of another cell was 
laid close to the old one. The workers were very 
excited over it, nibbling it a great deal. Now and 
then it almost disappeared, nevertheless the workers 
