NATURAL HISTORY. 



75 



besides stones ; let us hear something of them, 

 if you please." 



"Very willingly, boys. Some build of 

 shells : here are pictures of their nests. 



Shell Nests of Caddis-worms. 



Some build of leaves, and others of pieces of 

 reed or light bark. 



Reed Nest of Caddis- worm. 



And a curious thing about those which build 

 of light pieces of bark or reed is this, that they 

 will make the top-piece come over so as to 

 hide their heads, and prevent you from seeing 

 them. Some build of sand ; and then as the 

 house would be so light that the water run- 



