v SOCIAL HOMES 177 



which the builders are engaged, it draws out the little 

 mass with its jaws and feet into ribbon-like form along 

 the edge of the wall, reducing it to the requisite thin- 

 ness much as a mass of metal is pressed by the 

 cylinders of the rolling-mill. During the operation 

 the wasp invariably walks backwards. The tongue 

 then adds the finishing touches, giving the paper a 

 brightness and polish. A colony labour simultane- 

 ously, and the workers bring their morsels to the 

 same point of the nest, resulting in a regular trans- 

 verse zone. Every nest shows these zones of forma- 

 tion of the paper, sometimes not very distinct because 

 they vary simply from darker to lighter tones of gray ; 

 but often the stripes are quite pronounced and of dif- 

 ferent colours. The wasps go forth solitarily in search 

 of building material no doubt, and must bring in stuffs 

 of various sorts. But when one finds a good working- 

 stock, others seem to become cognisant of the fact and 

 hasten to the spot, and the zone constructed will be 

 of a particular colour. If, for example, a birch be the 

 object attacked, the zone will be white ; if a poplar, the 

 zone will be green. The same wasp, however, it has 

 been observed, does not always bring in a load of the 

 like colour. But she seems sensible enough not to 

 deposit her lump behind material different from her 

 own, she puts it against similar substance, and mixed 

 bands are never made. 



The separate sheets or leaves of paper are 

 not complete sacs, shutting in the combs as an 

 egg is inclosed in its shell. They are limited 

 in size and imbricate* with one another, and are 

 kept in place and are in contact together merely 



N 



