26 THE INSECT WORLD. 



Oryctes nasicornis, four times only. The bee can draw twenty 

 times the weight of its body ; Donacia nymphea* forty-two times 

 its own weight. 



From this it follows that if the horse possessed the same 

 strength as this last insect, or if the insect were the size of a horse, 

 they would either of them be able to draw 155,250 Ibs. M. 

 Plateau has ascertained the pushing power in insects, by introducing 

 them into a pasteboard tube, the interior of which was made rough, 

 and in which was fixed a glass plate, which allowed the light 

 to penetrate into the prison. The animal, if excited, struggled 

 with all its strength against the transparent plate, which, on being 

 pushed forward, turned a lever adapted to a miniature dynamo- 

 meter, which indicated the amount of eflPort exercised. 



The results thus obtained prove that the pushing power, like 

 the power of traction, is greater in inverse proportion to the 

 size and weight of the animal. A few figures will better explain 

 this curious law. In Oryctes nasicornis, the proportion of the 

 pushing power to the weight of the insect is only three to two ; 

 in Geotrupes stercorarius, it is sixteen to two ; and in Onthophagus 

 nuchicornis, seventy-nine to six. 



Experiments have been made on the lifting power of insects, 

 by fastening a ball of soft wax to a thread attached to the hind 

 legs. The proportion of the weight lifted has been found equal 

 to that of the body. That is to say, that the insect when flying 

 can lift its own weight. This is proved by the following calcula- 

 tions : In the Neuroptera the proportion is 1, in the Dragon-fly 

 (Libellula vulgata), '7 in Lestes sponsa. In the order Hymen- 

 optera, it is 78 in the bee, and -63 in Bombus terrestris, the 

 humble bee. In the Diptera it is -9 in Calliphora vomitoria,^ 1-84 

 in the Syrphus corolla, and T77 in the house-fly. 



These results show that insects have only sufficient power to 

 sustain their own weight when flying, as the above calculations 

 exhibit the maximum of which they are capable, and at the utmost 

 this strength would only compensate for the fatigue occasioned 

 by the action of flight. 



At the same time it is to be observed that the Diptera, and 

 among others the house-fly, can sustain their flight longer than the 

 * A beetle. ED. f The meat-fly. ED. 



