SOME SOCIAL WASPS 255 



two queens, 2 all clearly marked, were taken to the mail-box 

 exactly as before and liberated at 8 : 40 a. m. The route 

 was in all respects the same as previously, except that the 

 wheat in the field had just been cut and was now in shocks, 

 thus altering the aspect of the landscape. 



When the nests were examined at noon for any returns, 

 the queens had already arrived at nests 19 and 20, but not 

 one of the ten workers returned during the five succeeding 

 days. Some of these orphans were perhaps two days old, 

 while some might have been a week or ten days old. One 

 would at least expect a week-old worker to give positive 

 results in so simple an experiment, but since these workers 

 were all members of fairly large family groups, it may well 

 be that they had had little responsibility or practice in for- 

 aging, and hence were mere infants in experience. 



Before going further with the experiments, some factors 

 hi the biology and behavior of Polistes pallipes must be 

 introduced. 



When once a queen is lost, strayed or stolen from the 

 nest, one or more of the workers that are left, or, if there 

 be none at the time, of those that come afterwards, will in- 

 stinctively take up the duties of the queen, lay eggs and 

 constantly remain on the nest. Then, as is very generally 

 known, the eggs of the foster-mother give forth only male 

 wasps. This condition we now face nests ruled over by 

 an adopted mother. 3 



One other item in their behavior is at once noticeable : 

 when one attempts to take queens or old workers from 

 the nest, the slightest approach will cause their alertness, 

 sharp, nervous movements, antennae in motion and heads 



2 Nest 19, i queen and 3 workers ; nest 20, I queen ; nest 8, 3 workers, 

 and nests 13, K4, n and 18, I worker each. 



3 In Experiments V and VII they may hav< been too young to have 

 commenced their duties. 



