SOCIAL-WASPS. 61 



beneficent lustre, pleasingly contrasted with his uncle's 

 glory), there is an interesting example of this instinctive 

 adoption of the labours of others, " In the trans-Mississip- 

 pian territories of the United States, the burrowing-owl 

 resides exclusively in the villages of the marmot, or prairie- 

 dog, whose excavations are so commodious, as to render it 

 unnecessary that the owl should dig for himself, as he is 

 said to do where no burrowing animals exist.* The villages 

 of the prairie-dog are very numerous and variable in their 

 extent, — sometimes covering only a few acres, and at others 

 spreading over the surface of the country for miles together. 

 They are composed of slightly-elevated mounds, having the 

 form of a truncated cone, about two feet in width at the 

 base, and seldom rising as high as eighteen inches from the 

 surface of the soil. The entrance is placed either at the 

 top or on the side, and the whole mound is beaten down 

 externally, especially at the summit, resembling a much- 

 used footpath. From the entrance, the passage into the 

 mound descends vertically for one or two feet, and is thence 

 continued obliquely downwards imtil it terminates in an 

 apartment, within which the industrious prairie-dog con- 

 structs, on the approach of cold weather, a comfortable cell 

 for his winter's sleep. The cell, which is composed of fine 

 dry grass, is globular in form, with an opening at top, 

 capable of admitting the finger ; and the whole is so firmly 

 compacted, that it might without injury, be rolled over the 

 floor."t 



In case of need the wasp is abundantly furnished by 

 nature with instruments for excavating a burrow out of 

 the solid ground, as she no doubt most commonly does, — 

 digging the earth with her strong mandibles, and carrying 

 it off or pushing it out as slie proceeds. The entrance- 

 gallery is about an inch or less in diameter, and usually 

 runs in a winding or zigzag direction, from one to two feet 

 in depth. In the chamber to which this gallery leads, and 



* The owl observed by Vieillot in St. Domingo digs itself a burrow 

 two feet in depth, at the bottom of which it deposits its eggs upon a bed 

 of moss. 



t American Ornitholog}% by Charles Lucien Bonaparte, vol. i. p. 69, 



