ON THE CAPTURE OF FORMICARIOUS HISTERID.E. 291 



habit of removing their nests elsewhere. Of the middle-sized 

 stones, the best for the searcher's purpose are those which when 

 lifted expose all the galleries of the nests, as then the beetles, if 

 there, are seen at once ; but if the galleries are on a lower plane, 

 or at the edge of the stone, the soil must be pressed aside to give 

 a clear view of the excavations in which the larvse are being 

 reared. The Histeridse are generally found feeding on the larvfe, 

 attaching themselves to them by their mandibles and legs ; but 

 of course I also saw a good number in the galleries near where 

 the larvae were stored, this being the case especially with 

 S. hispanicus, arachnoides, and even fulvus, which are evidently 

 by habit more active than the shorter-legged species, as cancer 

 and punctulatus. When a nest is laid bare the first instinct of 

 the ant is to remove their larvae into the lower galleries, and 

 store them away out of the sun and air, and the Histeridse 

 follow them as quickly as possible, for, like all pale subterraneous 

 species, they are not comfortable in the light. 



I cannot record an instance of an ant molesting a beetle, and 

 it seemed to me they were either unconscious of their presence 

 or utterly indifferent to the mischief they were doing ; so much 

 so, that on two occasions I saw a Sternocoelis cling to the abdomen 

 of the AplicBnogaster, and ride into a lower gallery on its 

 back. At another time I saw Sternocoelis sticking to a mass of 

 larvae, which an ant was removing to a place of supposed safety, 

 after I had disturbed the domestic arrangements of the nest. 

 Ap)li<2nog aster seems to me to be weak in its mandibles, and it is 

 also deficient, as compared to Formica rufa and fidiginosa, in 

 formicic acid ; and this may point to one of the causes why 

 Hetcerius and Sternocoelis have been able to install themselves in 

 the nests of the ants, where they do an injury, which, from the 

 care the ants are seen to take of their larvae, we must presume 

 they would were they conscious of it, and able to retaliate, 

 violently resent. If an Hetcerius could be fixed between the 

 mandibles of an ant, I think it would be seen that the purchase 

 the ant could bring to bear on the comparatively hard exo- skeleton 

 of the beetle would be very slight, as the mandibles would in this 

 position be too far widened out to admit of much pressure. I 

 incline to the belief that the ants are physically incapable of 

 either freeing their nests of the intruders, or of destroying them 

 within it ; and am I crediting them with too much philosophy in 



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