x OBSERVATIONS ON PSITHYRUS 253 



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 Psithyrus 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 lapidarius 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 Psithyrus 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 



