The Yellow-winged Sphex 



the hidden retreat destined for the provisions 

 and the larvae. It is in this entrance-passage 

 that the Sphex takes shelter in bad weather; 

 it is here that she retires for the night and 

 rests for a few moments in the daytime, put- 

 ting outside only her expressive face, with its 

 great, bold eyes. Following on the vesti- 

 bule comes a sudden bend, which descends 

 more or less obliquely to a depth of two or 

 three inches more and ends in an oval cell 

 of somewhat larger diameter, whose main 

 axis lies horizontally. The walls of the cell 

 are not coated with any particular cement; 

 but, in spite of their bareness, we can see 

 that they have been the object of the most 

 conscientious labour. The sand has been 

 heaped up and carefully levelled on the floor, 

 the ceiling and the sides, so as to prevent 

 landslips and remove any roughness that 

 might hurt the delicate skin of the grub. 

 Lastly, this cell communicates with the pass- 

 age by a narrow entrance, just wide enough 

 to admit the Sphex laden with her prey. 



When this first cell is supplied with an egg 

 and the necessary provisions, the Sphex walls 

 up the entrance, but does not yet abandon 

 her burrow. A second cell Is dug beside the 

 first and victualled in the same way; then a 

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