THE GREAT OOLDEN DIGGER. 35 



the term, that the localities were in some way unsuitable and 

 that hence she had no occasion to return to them? Had she de- 

 cided, in the last instance, that she would return and so must 

 get I'.er bearings? We wondered how far the different acts 

 were instinctive, or were, as Huber has it, an evidence of a "lit- 

 tle dose of judgTuent." Bates, in speaking of Monedula signu- 

 ta, says that he often noticed in taking a few turns about the lo- 

 cality of its nest and that he was convinced that it was doing so 

 for the purpose of getting its bearings. Belt, ha,ving described 

 how he fed a specimen of Polistes carnifex with a caterpillar, 

 which the wasp cut into two parts, goes on to say: "Being at 

 the time amidst a thick mass of fine-leaved climbing plant, it 

 proceeded, before flying away, to take note of the place where 

 it was leaving the other half. To do this, it hovered in front 

 of it for a few seconds, then took small circles in front of it, 

 then larger ones around the whole plant. I thought it had gone, 

 but it returned again, and had another look at the opening in 

 the dense foliage down which the other half of the caterpillar 

 la."* He then remarks that when the wasp came back for the 

 remaining half it flew straight to its nest without taking any 

 further note of the locality. Both of these writers believe that 

 many of the actions of insects that are ascribed to instinct are 

 really evidence of the possession of a certain amount of reason- 

 ing power. 



To return to our Sphex. When she flew away we naturally 

 supposed that she had gone in search of her piey, and we were 

 on the qvi vive to observe every step in her actions when she 

 ■came home. Alas! when she came back half an hour later, she 

 was empty handed. She dug for four minutes, then flew off 

 and was gone two minutes, then returned and worked for thirty- 

 five minutes. Another two minutes' excursion, and then she 

 -settled down to work in good earnest and brought up load after 

 load of earth until the shadows grew long. We noticed that on 

 these later trips she flew directly away, depending upon her first 

 -careful study of the suroundings to find her way back. At 



*Naturalist in Nicaragua, p. 136. 



