154 



LIFE, IN ITS INTERMEDIATE FORMS. 



According to the same excellent authority, the Stag 

 Beetle (Lucanus cervus) has been known to gnaw a hole 

 an inch in diameter through the side of an iron canister 

 in which it was confined, and on which the marks of its 

 jaws were distinctly visible, as proved by Mr Stephens, 

 who exhibited the canister at one of the meetings of the 

 Entomological Society. 



Let us look at the powers of Insects exercised in the 

 act of flying. The House-flies (Musca domestica), that 

 wheel and play beneath the ceiling for hours together, 

 ordinarily move at the rate of about five feet per second ; 

 but if excited to speed, they can dart along through thirty- 

 five feet in the same brief space of time Now in this 

 period, as Kirby and Spence observe, " a race-horse could 

 clear only ninety feet, which is at the rate of more than 

 a mile in a minute. Our little fly, in her swiftest flight, 

 will in the same space of time, go more than one-third of 

 a mile. Now compare the immense difference of the size 

 of the two animals (ten millions of the fly would hardly 

 counterpoise one racer), and how wonderful will the velo- 

 city of this minute creature appear ! Did the fly equal 

 the race-horse in size, and retain its present powers in the 

 ratio of its magnitude, it would traverse the globe with 

 the rapidity of lightning."* Some of the flies that haunt 

 our gardens shoot along so rapidly that the eye cannot 

 follow them in flight. 



Nor are these tiny creatures less masters of the arts of 

 running and leaping. De Lisle mentions a fly so minute 

 as almost to be invisible, which ran nearly six inches in a 

 second, and in that space was calculated to have made 



* Introd. to Entomology. 



