NATURAL HISTORY. 173 



mean the way in which they will sometimes 

 place their eggs. The kind of moth that does 

 this work is not exactly known, but natural- 

 ists think that the eggs are moth's eggs, be- 

 cause they are covered with the down, exactly 

 like those which are known to be moth's eggs. 

 These eggs are twisted round a branch, like 

 the thread of a screw, or like the curled end 

 of a corkscrew put over a small stick. Here 

 is a picture of some of these eggs." 



Spiral group of Eggs of an unknown Moth. 



" Ah, this is wonderful work indeed for a 

 moth, Uncle Philip." 



" As you seem to like this, boys, I will just 

 mention to you that there is another moth, 

 called the lackey-moth, which winds its eggs 

 also around a branch. They are hard, how- 

 ever, and not covered with any down, and are 

 put on in the strongest possible way. If men 

 wish to make an arch of stone, you know that 

 the stones will be more narrow at the bottom 



