48 



PSYCHE 



[June 



not a change had been made. The last change, I think, was usually made in the 

 spring following the year in which the eggs were hatched ; that is to say, they 

 usually winter in the nymph stage. In confinement, however, 1 have had them 

 winter also in the adult stage. 



All the young up to the last nymph stage have ten plates, oi tergites, on the 



dorsal surface between the last pair of legs and the terminal forceps. In the last 

 part of the nymph stage, however, some of the females have only nine plates fully 

 showing, with just the tip of a tenth. I found that this was due to the fact that 

 the plate next to the last — that is, the ninth — gradually slid under the one ante- 

 rior to it — or the eighth — until it was nearly lost to sight. No male earwig that 

 I have ever seen had this peculiarity. 



