COLEOPTERA. — SILPHID.^. 137 



mens recently arrived at the perfect state, nor by such as have long 

 fasted; whence, as Olivier sujiposes, it is from the nature of tlieir 

 food that these insects derive their disgusting scent, which is some- 

 times so strong as to penetrate every thing in the immediate neigh- 

 bourhood, and which has been known to be retained for upwards of 

 twenty years without diminution, or without the insect losing any- 

 thing in weight. The fluid which they emit also serves to mollify 

 the substance upon which they feed, forwarding its decomposition, 

 or being useful as a means of defence. The wonderful instinct of 

 these insects, on the other hand, renders them objects of interest, and 

 ot which the proceedings of the Sexton beetles (Necrophorus) de- 

 tailed by Gleditsch in his Recreations of Natural History (^Physical 

 Botan. CEcon. Abhandl. Halle, 1765) offer an admirable example. 

 These insects are powerful for their size, and run well ; tlieir (light is 

 also very strong, the wings being long; their elytra during flight are 

 carried in an upright position, their upper surfaces being almost 

 brought into contact. The insect produces a slight but sharp kind 

 of noise by the friction of its abdomen against the elytra. These 

 insects are not uncommon ; and no sooner is any small dead animal, 

 bird, or bit of flesh exposed in the open air, than the Sexton beetles 

 make their appearance ; and after rigorously inspecting the object, as 

 it were for the purpose of taking its dimensions, several of them 

 commence operations by creeping beneath the carcass, where, by 

 digging away the earth with their fore-legs beneath and around the 

 animal, it by degrees descends into the ground, although many times 

 larger than the insects engaged in burying it ; they then cover it with 

 earth, and sometimes, indeed, bury it nearly a foot deep, the opera- 

 tion occupying only a ?*i\v hours. In this labour the males assist, 

 and soon after it is accomplished the females deposit their eggs in 

 the carcass. The autlior above mentioned also records a still stronger 

 instance of instinct exhibited by the same insects ; some of which, 

 in order to get possession of a mole fastened to a stick stuck upright 

 in the ground, undermined the stick so that it soon fell to the earth. 

 From an observation of M. Cadet de Vaux, it appears that whilst 

 several individuals of Necrophorus vespillo labour in concert, the 

 larger Necr. germanicus works alone; and according to liatreille the 

 larvae of the Necrophori entirely consume the buried carcass, leaving 

 neither skin nor bones. Hence it seems that the number of labourers 

 is proportioned to the quantity of food necessary for the support of 



