How Animals Work. 



on to the side of the first, and upon the same horizontal 

 line. This second cell is provisioned and sealed up 

 in the same way as the first, and then a third, fourth, 

 fifth, and sometimes up to an eighth, are added. The 

 external surface of the finished nest is marked by long 

 depressions which correspond with the intervals be- 

 tween the cells ; while the lower part of the nest is 

 thinner than the rest, and when the larvae have become 

 full grown, changed to pupae, and completed their 

 transformations, the adult wasps bite their way out 

 from this part, and leave open holes showing where 

 they have made their escape. 



Mr. Bates during his sojourn at Santarem and ex- 

 ploration of the Amazon had many opportunities of 

 watching the habits of the Solitary Wasps of those 

 regions, and gives the following account of an interest- 

 ing little worker in clay called Pelopceus fistularis : " It 

 collected the clay in little round pellets, which it carried 

 off, after rolling them into a convenient shape, in its 

 mandibles. It came straight to the pit with a loud 

 hum, and on alighting lost not a moment in beginning 

 its work finishing the kneading of its little load in 

 two or three minutes. The nest of this species is 

 shaped like a pouch, two inches in length, and is at- 

 tached to a branch or other projecting object. One 

 of these restless artificers once began to build on the 

 handle of a chest in the cabin of my canoe when we 

 were stationary at a place for several days. It was so 

 intent upon its work that it allowed me to inspect the 

 movements of its mouth with a lens whilst it was laying 

 on the mortar. Every fresh pellet was brought in with 

 a triumphant song, which changed to a cheerful busy 



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