1634 THE STORY OF THE UNIVERSE 



it itself by twisting in its beak spiders' webs, bits of 

 cotton, and little ends of wool. Sykes found that the 

 threads used for sewing were knotted at the ends. 

 It is impossible not to admire animals who have skil- 

 fully triumphed over all the obstacles met with in the 

 course of these complicated operations. 



Certain spiders, while they do not actually sew in 

 the sense that they perforate the leaves they use to 

 build their nest, and draw the thread through them, 

 yet subject the leaves to an operation which can not 

 well be called anything else but sewing it. 



Certain wasps, by the material of their dwellings, 

 approach the Japanese ; they build with paper. This 

 paper or cardboard is very strong and supplies a solid 

 support; moreover, being a bad conductor of heat, it 

 contributes to maintain an equable temperature 

 within the nest. The constructions of these insects, 

 though they do not exhibit the geometric arrange- 

 ment of those of bees, are not less interesting. The pa- 

 per which they employ is manufactured on the spot, as 

 the walls of the cells develop. Detritus of every kind 

 enters into its preparation : small fragments of wood, 

 sawdust, etc. ; anything is good. These Hymenoptera 

 possess no organ specially adapted to aid them; it is 

 with their saliva that they glue this dust together and 

 make of it a substance very suitable for its purpose. 

 The dwellings often reach considerable size, yet they 

 are always begun by a single female, who does all the, 

 work without help until the moment when the first 

 eggs come out; she is thus furnished with workers 

 capable of taking a share in her task. The Vespa 

 sylvestris builds a paper nest of this kind, hanging to 



