Wasps 



described by all of the authors above mentioned. When the 

 burrow is complete the female wasp has been observed to use a 

 stone as a tamping iron to pack the earth into the mouth of the 

 burrow. This is the tool use referred to. Dr. Williston states 

 that he feared to publish his observation at first, since he might 

 not be believed. Pergande noticed that after the burrow was 

 completed and filled the mother wasp revisited the spot oc- 

 casionally to satisfy herself that everything was secure against in- 

 truders and to make surety doubly sure by placing additional dis- 

 guising objects over the already disguised burrow mouth. 



It was in their study of one of the Ammophilas that the 

 Peckhams noticed a very distinct personality among the females 

 which they watched at work. This personality was not of in- 

 dividual appearance but of such mental attributes as careful 

 painstakingor carelessness and industry or laziness. One seemed 

 to hurry tremendously and spent no time on non-essentials. 

 Another was an artist, working for a long time on the closing of 

 her burrow, arranging the surface with scrupulous care and 

 sweeping away every particle of dust to a distance. Still another 

 went to the extreme in carelessness, carrying the caterpillar in a 

 very careless way and making a nest which was a very poor 

 affair. Still a fourth was "the most fastidious and perfect little 

 worker of the whole season, so nice was she in her adaptation of 

 means to ends, so busy and contented in her labor of love, and 

 so pretty in her pride of her completed work." In fact, they seem 

 to have almost as much individuality as human beings and the 

 result of these observations has a strong bearing on the discussion 

 of instinct. Fabre, the French entomologist, who studied the 

 same insects, considered that they were inspired by automatic- 

 ally perfect instincts which can never have varied to any ap- 

 preciable extent from the beginning of time. Deviation from the 

 regular rule, he thought, would mean extinction. The Milwaukee 

 authorities, however, found that variability was the one unmis- 

 takable and ever present fact, and this variability existed in every 

 particular, in the shape of the nest and in the manner of dig- 

 ging it, whether it is left closed or open, in the manner of 

 stinging the prey and of crushing it, in the manner of carrying 

 the victim, in the way of closing the nest and in the condition 

 produced in the victim by the stinging, some dying and others 

 living for a long time, though nearly motionless. All this varia- 



