SOME SOCIAL WASPS 291 



Polistes pallipes Lepel. 



We had long been possessed of an idle curiosity to know 

 how Polistes would behave if their nests were turned upside 

 down, so the experiment was tried of inverting several of 

 the nests of P. pallipes. This was done by taking down the 

 nest, passing a long hat-pin through the center and stem of 

 the nest, and thus pinning it back in its place upside down, 

 with ample space allowed above for the easy entrance and 

 exit of the wasps to the cells. 



After one of the Polistes nests had been inverted, the 

 inmates removed much of the material from the nest and 

 commenced to build another nest on the ceiling at the 

 identical spot where this one had been. At last only one 

 wasp at a time was to be seen working at this spot, while 

 the others remained below and cared for the inverted nest- 

 lings. In time, the wasps abandoned this new project and 

 all worked on the inverted nest, carrying on the household 

 affairs in the usual way, excepting that they removed the 

 material from the middle of the nest and from it this 

 time built other normal cells beneath, using the roof of the 

 old nest, now inverted, for the ceiling of the new cells. 



In another colony, the duties went on normally, and none 

 of the new cells were placed vertically on the old roof (now 

 ceiling), but the new cells around the periphery were so 

 built as to be almost horizontal, radiating from the stem of 

 the nest. 



In two other inverted colonies, the affairs of the house- 

 hold went on normally, but no attempt was made to add 

 new cells. 



A year later, in June, when turning over a large stone, 

 we found a queen of P. v&riatus Cress, with her nest of a 

 dozen cells, two of which were sealed and the others with 

 wasplings in various stages of development. We inverted 



