86 FIRST BOOK OF ZOOLOGY. 



tered to the wall, rougli and irregular in appearance, and at 

 iirst sight might be mistaken for the work of some mis- 

 chievous boy. 



Pig. &±.— a Mud-WaspV Nest, having Two Cells. 



Fig. 84 represents their general appearance, for, rough 

 as tliej' appear, on close examination they are seen to be 

 constructed very systematically — the soft clay of which 

 they are built being laid on in alternate layers, looking 

 something like a braid ; while the upper portion, being built 

 of looser and coarser material, is put on in irregular lumps. 

 With a thin-bladed knife these mud-cells may be scraped off, 

 and sometimes can be pulled away with the fingers. Upon 

 opening them they will be found either filled with little 

 spiders, or containing yellow-colored larvas pupse in brown 

 skins, or wasps. Their history is as follows : 



S'2. When the mother-wasp gets ready to lay her eggs, 

 she first Imilds these curious nests of mud, A\-hich she collects 

 from the streets, or l)y the sides of brooks in clayey soil. Hav; 

 ing finished one cell, she deposits therein an egg, and then 

 collects a number of small spiders with which she completely 

 fills the cell. After this is done she closes iip the top of the 



