72 CONVERSATIONS ON 



It seems wonderful that so small an insect 

 should have so much strength. Here is a 

 picture of its jaws, seen through a microscope, 

 so as to appear a great deal larger than they 

 really are. 



Jaws of Mason- wasp. Greatly magnified. 



" I do not know, boys, that the masons we 

 have been talking of, show us any tools like 

 those with which men who are masons work ; 

 but they show us, at any rate, how to make 

 mortar by kneading or working it together ; 

 and they certainly show us that we were not 

 the first who built walls. But there is an- 

 other kind of mason who works in stone. 

 He picks out the stones which are of proper 

 size, and he fastens them together with mor- 

 tar really as men do." 



" Pray tell us of him, Uncle Philip." 



" I will. The insect I mean is the caddis- 



