26 ~ THE INSECT WORLD. 
Oryctes nasicornis, four times only. The bee can draw twenty 
times the weight of its body ; Donacia nymphee,* 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 imsect were the size of a 
horse, they would either of them be able to draw 155,250 lbs. 
M. Plateau has ascertained the pushing power in insects, by intro- 
ducing 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 
dynamometer, which indicated the amount of effort exercised. 
The results thus obtained prove that the pushing power, like 
the power of traction, is greater in imverse 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 sect when fiying 
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,t 1:84 
in the Syrphus corolle, and 1-77 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.—Ep. + The meat-fly.— Ep. 
