PAPER-MAKERS 171 



There is considerable difference in the paper 

 made by the various species of wasps. That of 

 the Tree Wasps is smoother and much more regular 

 in its surface than that of the underground species, 

 which is made in semicircular lines which give it 

 ruggedness and inequality. One would almost 

 expect that an underground nest, being protected 

 all around by earthen walls, would not be furnished 

 by paper walls in addition. But they are apparently 

 necessary to equalize temperature as well as to 

 keep off emanations of damp from the soil and the 

 percolation of rain through the roof of the cavern. 



A good idea of the industry and the numbers 

 of a colony of wasps can be gained by sitting down 

 near the entrance to one of these subterranean 

 nests and noting the exits and entrances of the 

 workers. There is always sufficient room in these 

 passages to allow wasps going in opposite directions 

 to pass each other without any danger of jostling. 

 Mr. and Mrs. Peckham, in giving the results of 

 some observations they conducted in this way 

 say : 



" Experiments that would have been dangerous 

 to life and limb had we tried them with a paper 

 nest hanging in the open, were easy here, so long 

 as we kept calm and unflurried. Intent upon their 

 own affairs, and unsuspicious of evil, perhaps 

 because they knew themselves to be armed against 

 aggression, they accepted our presence, at first 

 with indifference ; but as we sat there day after 

 day we must have become landmarks to them, a^d 



