THE SOCIAL WASPS. 349 



the path by which she had left it. Experiments were also made by 

 moving the nest as soon as the locality-study had been made, and seeing 

 whether the wasp returned to the place where the nest had been. 

 Invariably the wasp did return to the exact former site of the nest, but 

 considerable variation was shown in the ability to find the nest in its 

 new location. One wasjj had no difficulty, when the nest had been moved 

 a distance of eighteen inches ; others were unable to do so if moved more 

 than eight inches. In one instance, the site of the nest was changed 

 while the wasp was sipping honey from a dish about fourteen inches 

 away. Eeturning, and not finding its nest in the usual place, the wasp, 

 in circling, reached the honey dish once more, and again started for the 

 nest along essentially the same path. This was repeated eight times 

 before the wasp in its explorations finally reached its nest and rested 

 there. The whole performance looked as though the wasp were con- 

 sciously using the honey dish as a landmark. It started out from this 

 point each time, the same way as a person might, when he became 

 aware that he was making some mistake in finding his way to a desired 

 destination. 



It would be interesting to speculate on the meaning of the various 

 actions described above. What sense best serves Polistes in finding 

 its way about? Does it actually see and make a mental note of the 

 various factors of its environment? Or does a mere blind following in 

 response to other sense impressions, namely, the olfactory, serve its 

 purpose ? Theory is fascinating, but with the slight data at command, 

 it is hardly profitable. Observation shows that the wasp instinctively 

 flies toward the light; its course is also materially affected by currents 

 of air, such as draughts in a room where it is held captive. Mechanical 

 response to these two influences will, in this case, usually serve to 

 liberate it without the use of any other sense or faculty. Again, the 

 antennae seem to play an important role in orienting the insect. Acci- 

 dental loss of one antenna in one case retarded the finding of the 

 nest. Further, the flight in circles, when leaving or approaching the 

 nest, might be interpreted as due to the difference in stimulation of 

 the antennae of the two sides — the side toward, and the side away, from 

 the nest; and the flight straight to the nest, when the wasp has poised 

 for a moment with both antennae directed toward the nest, seems to add 

 evidence in favor of this view. However, further experimentation is 

 necessary before it is possible to attempt a satisfactory explanation. 



During the cold days of autumn, when there are no more larvae to 

 rear, about the only activity observed on the nest is that occasioned by 

 the home-coming of a member of the wasp family. This one is tumul- 

 tuously set upon by the half dozen wasps nearest him, each of which 

 is favored with an embrace which is amusingly like the affectionate 

 demonstrations shown on the return of a human being to his family 



