82 INSECT LIFE 



VI 



would think they were a troop of merry comrades, 

 stimulating one another to work by a cadenced 

 rhythm. Meanwhile, the sand flies, falling in fine 

 dust on their quivering wings, and the heavier 

 gravel, pulled out bit by bit, rolls far away. If 

 a bit resist too much, the insect goes at it with 

 a high note, reminding one of the cry with which 

 a woodcutter accompanies the stroke of his axe. 

 Under the redoubled efforts of tarsi and mandibles 

 the cavity is already sketched out, and the Sphex 

 can already dart into it. Then comes a lively inter- 

 change of forward movements to detach material, 

 and of backward to brush out fragments. In this 

 hurried coming and going the Sphex does not so 

 much walk as dart forward, as though impelled by 

 a spring. With panting abdomen, antennae vibrat- 

 ing, the whole body moved by a strong thrill, she 

 springs forward and is out of sight. You still hear 

 the unwearied hum underground, and one sees from 

 time to time hind legs pushing backward a wave 

 of sand to the mouth of the burrow. From time to 

 time labour underground is interrupted either that the 

 Sphex may dust herself in the sunlight, and get rid 

 of grains of dust which insinuate themselves into 

 delicate joints and hamper the liberty of her move- 

 ments, or that she make a reconnaissance in the neigh- 

 bourhood. Notwithstanding these short interrup- 

 tions, in a few hours the gallery is hollowed out 

 and the Sphex appears on her threshold, to voice her 

 triumph, and give the last touch to her labours by 

 effacing some inequality, or carrying away some 

 particles of earth, the objection to which only the 

 eye of a Sphex could perceive. 



