2 . THE INSECT WORLD. 



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 

 t4uld either of th^m be able to draw 155,^50 lbs M. bateau has 

 ascertained the pushing power in msects, by introducing them into a 

 Dasteboard tube, the interior of which was made rough, and m which 

 was fixed a dass plate, which allowed the light to penetrate mto the 

 mison. The animal, if excited, struggled with all its strength agamst 

 ihe transparent plate, which, on being pushed forward turned a lever 

 adapted to a miniature dynamometer, which indicated the amount of 



effort exercised. n ^ <-i.<^ 



The results thus obtained prove that the pushing power, like the 

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

 weidit 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 ; m Geotrupes sterco- 

 rarius it is sixteen to two ; and in Onihophagus nuchicorms 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 hmd legs. 

 The pro'portion 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 

 weio-ht. This is proved by the following calculations :— In the 

 Neuroptera the proportion is i in the Dragon-fly {Libellula vulgata\ 

 •7 in Lestes sponsa. In the order Hymenoptera it is 78 m the bee, 

 and -63 in Bombus terrestris, the humble-bee. In the Diptera it is 

 •9 in Calliphora vomitoria* 1-84 in the Syrphus coroUcB, and 177 m 

 the house-fly. . 



These results show that insects have only sufticient power to 

 sustain their own weight when flying, as the above calculations 

 exhibit the maximum oT" 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 

 Hymenoptera and Neuroptera, although one would not think _ so 

 from their appearance. In conclusion, if an insect's power of flying 

 is not considerable, its power of traction and propulsion are immense, 

 compared with the vertebrate animals ; and, in the same group of 

 insects, those that are the smallest and Hghtest are the strongest. 

 The proportion between the muscular strength of insects and the 



* The meat-fly.— Ed. 



