284 MUSCULAR DYNAMOMETRY. 



Fasten to the insect's pincer, or forceps, with a thread, a 

 halfpenny, which will weigh about two grains, while the weight 

 of its body, on an average, will not exceed five centigrammes. 

 Give the insect free course over a sheet of paper, and you 

 will see it drag along the coin like a light chariot. Our ani- 

 mal is, therefore, capable of drawing a burden fifty times 

 heavier than its own body. A man of eleven stone would, 

 in the same ratio, be able to drag 7700 Ibs. Neither man 

 nor horse can enter, in this respect, into competition with 

 the earwig. If all the members of the animal kingdom were 

 classified according to their power of traction, it is probable 

 that the post of honour at the top of the list would be occu- 

 pied by our despised Forficula auricularia. 



The idea of a muscular dynamometry of insects is not so 

 new as one might be tempted to think it. From time imme- 

 morial men have been struck, without being able to account 

 for it, by the enormous disproportion existing between the 

 weight of a flea and the force or energy displayed by its 

 extraordinary bounds. Hence the popularity of a recent ex- 

 hibition in London of Performing Fleas. Pliny, eighteen 

 centuries ago, asserted that the muscular strength of the ants 

 exceeded that of all other animals, if we compared the burden 

 they were able to carry with the diminutiveness of their bodies. 

 " Si quis comparet onera corporibus earum, fateatur nullis por- 

 tione vires esse majores" * 



In the seventeenth and eighteenth centuries, this interesting 

 * Pliny, "Hist. Nat.," xi. 36. 



