456 NATURE'S TEACHINGS. 



inches, and then sinks slowly down, with the white gills 

 floating on either side. 



Should a Dragon-fly larva be near, it sees the grub ascending, 

 glides quietly under it without using its legs so as to cause 

 alarm, waits for it to sink, darts out the mask, seizes it in the 

 jaws, drags it to its mouth, and the grub is seen no more. 'So 

 voracious are these larvae, that, if only two are kept in the same 

 vessel, one is sure to devour the other. 



ANOTHER good example of the Lazy-tongs is the Proboscis of 

 the common House-fly. We have all seen these insects alight 

 near sugar, or any other tempting food, unfold the proboscis, 

 pour a drop of liquid in the sugar, dissolve it, suck it up, and 

 then shut up the proboscis as if by hinges. 



ANOTHER labour-saving machine is the Apple-parer, a com- 

 paratively modern invention. The principle is, that a knife is 



8QUIKBEL AND NUT. APPLE-PAGER. 



pressed lightly by a spring against a revolving apple, and set 

 at such an angle that nothing but the outside peel can be 

 removed. Where large numbers of apples have to be pared, as 

 in making preserves or in hotels, this is a most useful inven- 

 tion. 



When I first saw it at work, the operation seemed familiar 

 to me, but I could not at first remember the parallel. At last 

 it flashed across me that a Squirrel eating a nut was the natural 

 parallel of the Paring Machine. 



After splitting the shell and extracting the kernel, the 



