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TEXT-BOOK OF ENTOMOLOGY 



weakest insects pull at least five times their own weight ; many of 

 them, however, get the better of a burden twelve to twenty fold as 

 heavy as themselves, while a strong man or a draught horse, for 

 example, is not even able to pull a burden which is equal to the 

 weight of his body. Plateau came to the following results as to the 

 relation of the weight of the body to the load drawn (I and 2 are to 



FIG. 237. Vespa crabro, worker, fixed by heat and alcohol some hours after leaving its cell. 

 A x 425; J3 to /) x 850 times : A, muscular fibre of the motor muscles of the mandibles treated, for 

 ten minutes, by 1 per cent potassium to bring out the reticulutn ; the nodes of union of the rayed 

 filaments with the longitudinal filaments are indicated by distinct granulations (l.d), and these longi- 

 tudinal filaments present accessory thickenings (d.a) ; T, trachea ; N, junction of a nervous filament 

 with the muscular fibres. , fibre of the same muscle, not treated with potassium, stained by 

 haematoxylin ; (7, transverse section of a disk at the level of a layer of rayed filaments; Stiri-, 

 sarcolemma. Z>, transverse section of a disk at the level of the rods ; nuc, nucleus. After Janet. 



be compared with each other, 1 being the larger, and 2 the smaller 

 insect ; it will be seen that the smaller insect is the stronger). 



1. Carabus auratus 17.4. 



2. Nebria brevicollis 25.3. 



1. Cetonia aurata 15. 



2. Trichius fasciatus 41.3. 



1. Melolontha vulgaris 14.3. 



2. Anomala frischii 24.3. 



1. Oryctes nasicornis 4.7. 



2. Geotrupes stercorarius 9.8. 



3. Onthophagusnuchicornis 14.4. 



1. Necrophorus vespillo 15.1. 



2. Silpha lii'ida 24.4. 



1. Ocypns morio 17. 



2. Quedeus fulgidus 29.6. 



1. Donacia nyinph<i-<i' 42.7. 



2. Crioceris merdigera 39.2. 



1. Bombus terrestris 16.1. 



2. Bombus rupestris 14.5. 



3. Apis mellifica 20.2. 



As regards the pushing power, the relation of the load to the size 

 of the body in different large beetles, gave the following figures : 



Oryctes nasicornis 3.2. 

 Geotrupes stercorarius 28.4. 

 Onthophagus nuchicornis 92.9. 



