The Mason-Wasps 



tained between several wrappers enclosed 

 one within the other, the Common Wasp, 

 no less versed in the laws of thermal science, 

 arrives at the same result by different means. 

 With her paper-pulp she manufactures broad 

 scales which overlap loosely and are super- 

 imposed in numerous layers. The whole 

 forms a coarse blanket, of a thick, spongy 

 texture and well-filled with stagnant air. 

 The temperature under such a shelter, in the 

 hot weather, must be truly tropical. 



The fierce Hornet (Vespa crabo, Linn.), 

 chief of the Wasp clan by virtue of her 

 strength and her warlike audacity, con- 

 forms to the same principles of the globular 

 configuration and of air imprisoned between 

 partition-walls. In the cavernous hollow of 

 a willow or in the recesses of some empty 

 granary, she manufactures a yellow, striped, 

 very brittle cardboard, composed of an 

 agglomeration of woody fragments. Her 

 spherical nest is wrapped in an enclosure of 

 broad convex scales, a sort of tiles which, 

 welded to one another and arranged in mul- 

 tiple layers, leave between them wide in- 

 tervals in which the air is held motionless. 



To employ an athermous substance such as 

 air, in order to check the loss of heat; to an- 

 ticipate our manufacturers of eiderdown 

 248 



