78 NATURE'S TEACHINGS. 



minating silver, or other explosive compound, and is let loose, 

 when wanted, by the aid of fire. 



IN the illustration are represented on the right hand the 

 blow- guns of America and Borneo, and below them is the 

 cannon as at present made. On the left hand of the same 



CHOETODON, OB ARCHER-FISH. BLOW-GUNSCANNON. 



illustration is seen a representation of a natural gun which has 

 existed for thousands of years before gunpowder was invented, 

 and very long before the savage of Borneo or America dis- 

 covered the blow-gun. 



It is the ARCHER-FISH (Chcetodon), which possesses the curious 

 power of feeding itself by shooting drops of water at flies, and 

 very seldom failing to secure its prey. 



There are several species of this very curious fish spread 

 over the warmer parts of the world, and their remarkable mode 

 of obtaining prey is very well known in all. There is, indeed, 

 scarcely any phenomenon in Nature more remarkable than the 

 fact of a fish being able to shoot a fly with a drop of water 

 projected through its tubular beak, if we may use that expres- 

 sion for so curiously modified a mouth. 



Indeed, so certain is the fish of its aim, that in Japan it is 

 kept as a pet in glass vases, just as we keep gold fish in 

 England, and is fed by holding flies or other insects to it 

 on the end of a rod a few inches above the surface of the 

 water. The fish is sure to see the insect, and equally sure 

 to bring it down with a drop of water propelled through its 

 beak. 



It is worthy of remark that the same principle was once, 

 though unsuccessfully, employed in the propulsion of carriages, 

 under the name of the Pneumatic Railway. Some of my 

 readers may remember the railway itself, or at all events the 

 disused tubes which lay for so many years along the Croydon 



