INSECT PIRATES AND SUBMARINES 115 



excellence of action and control, put to shame all 

 human efforts along the same line. These are the 

 water boatmen, stout boat-shaped insects whose 

 hind legs are long, projecting outward like the 

 oars of a rowboat. They feather their oars, too, 

 or rather the oars are feathered for them, a fringe 

 of long hairs growing out on each side of the 

 blade. Some of the boatmen swim upside down, 

 and these have the back keeled instead of the 

 breast. Like real submarine boats, these insects 

 have to come up for air occasionally; and, again 

 like similar craft of human handiwork, their prin- 

 cipal mission in life seems to be warfare upon the 

 weaker creatures about them. 



Upon their bodies are many short hairs that 

 have the power of enclosing and retaining a good- 

 sized bubble of air. Thus the little boatman is 

 well supplied for each submarine trip, and he does 

 not have to return to the surface until all this 

 storage air has been exhausted. In perfectly pure 

 water, however, these boatmen can remain almost 

 indefinitely below the surface, although it is not 

 known how they obtain from the water the oxygen 

 which they usually take from the air. 



All of these skaters and boatmen thrive in small 

 aquariums, and if given pieces of scraped meat 

 Nvill live in perfect health. Here is an alluring 

 opportunity for anyone to add to our knowledge 

 of insect life ; for the most recent scientific books 

 admit that we do not yet know the complete life 



