SENSE OF DIRECTION 



opening. The contrast between the dehberate move- 

 ments of Astata and the rapid flight of Cerceris is very 

 striking. 



We have now given a sufficient number of instances, 

 from widely separated genera, to show the care that is 

 taken by wasps to acquaint themselves with the sur- 

 roundings of their nests. It has also been shown that 

 in spite of all this care they frequently have trouble in 

 finding their way about. All these facts have led us to 

 conclude that wasps are guided in their movements by 

 their memory of locahties. They go from place to place 

 quite readily because they are famiHar with the details 

 of the landscape in the district they inhabit. Fair eye- 

 sight and a moderately good memory on their part are 

 all that need be assumed in this simple explanation of 

 the problem. 



